mid-15c. (earlier ren, late 14c.), "a spell of running, the act of running," from run (v.).
The Old English noun ryne/yrn (early Middle English rine) meant "a flowing, a course, a watercourse;" the modern sense of "small stream" is recorded from 1580s, mostly in Northern English dialect and American English. The sense of "a flowing or pouring, as of liquid" is by 1814. In reference to the action of a school of fish moving together, especially upstream or in-shore, by 1820.
From 1804 as "place where anything runs or may run." The meaning "the privilege of going through or over, free access" is from 1755. In. U.S. baseball, "feat of running around the bases without being put out" by 1856; the sense in cricket is from 1746.
Meaning "continuous stretch" (of something) is from 1670s. That of "continuous use, circulation, or observance" (as in run of luck) is by 1714. The general sense of "a continuous series or succession" has yielded many specific meanings, as "three or more playing cards in consecutive order" (1870). In music, "a rapid succession of consecutive tones," by 1835.
The financial meaning "extraordinary series or rush of demands on a bank, etc." is recorded from 1690s. The market sense of "sustained demand for something" is by 1816.
From 1712 as "a spell of sailing between two ports;" hence also "an excursion trip" (1819); "single trip by a railroad train" (1857); the military aircraft attack sense (as in bombing run) is from 1916. Hence also "a regular round in a vehicle" (as in paper run, milk run, etc.).
In printing, the meaning "total number of copies done in a single period of press-work" is from 1909. In publishing, "set or series of consecutive numbers of a periodical," by 1889.
Meaning "tear in a knitted garment or stocking" is from 1922, probably on the notion of "a failure caused by looseness, weakness, or giving way;" to run had a specialized sense in reference to machinery, "to slip, go awry" (1846), and in reference to lace it meant "to unravel, come undone" (1878). Also compare running stitch "loose, open stitch" (1848).
Phrase a run for one's money "satisfaction for trouble taken" is from 1872 in a figurative sense, from horse racing, where it implied real competition (1841).
Old English gast "breath; good or bad spirit, angel, demon; person, man, human being," in Biblical use "soul, spirit, life," from Proto-West Germanic *gaistaz (source also of Old Saxon gest, Old Frisian jest, Middle Dutch gheest, Dutch geest, German Geist "spirit, ghost"). This is conjectured to be from a PIE root *gheis-, used in forming words involving the notions of excitement, amazement, or fear (source also of Sanskrit hedah "wrath;" Avestan zaesha- "horrible, frightful;" Gothic usgaisjan, Old English gæstan "to frighten").
Ghost is the English representative of the usual West Germanic word for "supernatural being." In Christian writing in Old English it is used to render Latin spiritus (see spirit (n.)), a sense preserved in Holy Ghost. Sense of "disembodied spirit of a dead person," especially imagined as wandering among the living or haunting them, is attested from late 14c. and returns the word toward its likely prehistoric sense.
Most Indo-European words for "soul, spirit" also double with reference to supernatural spirits. Many have a base sense of "appearance" (such as Greek phantasma; French spectre; Polish widmo, from Old Church Slavonic videti "to see;" Old English scin, Old High German giskin, originally "appearance, apparition," related to Old English scinan, Old High German skinan "to shine"). Other concepts are in French revenant, literally "returning" (from the other world), Old Norse aptr-ganga, literally "back-comer." Breton bugelnoz is literally "night-child." Latin manes probably is a euphemism.
The gh- spelling appeared early 15c. in Caxton, influenced by Flemish and Middle Dutch gheest, but was rare in English before mid-16c. Sense of "slight suggestion, mere shadow or semblance" (in ghost image, ghost of a chance, etc.) is first recorded 1610s; sense of "one who secretly does work for another" is from 1884. Ghost town is from 1908. Ghost story is by 1811. Ghost-word "apparent word or false form in a manuscript due to a blunder" is from 1886 (Skeat). Ghost in the machine was British philosopher Gilbert Ryle's term (1949) for "the mind viewed as separate from the body." The American Indian ghost dance is from 1890. To give up the ghost "die" was in Old English.
"the black liquor with which men write" [Johnson], mid-13c., from Old French enche, encre "dark writing fluid" (12c.), earlier enque (11c.), originally enca, from Late Latin encaustum, from Late Greek enkauston. This is the neuter of the past-participle adjective enkaustos "burned in," from the stem of enkaiein "to burn in," from en- "in" (see en- (1)) + kaiein "to burn" (see caustic).
In Pliny the word is the name of a kind of painting executed by fire or heat. Later it was the name of the purple-red ink, the sacrum encaustum, used by the Roman emperors to sign their documents; this was said to have been obtained from the ground remains of certain shellfish, formed into writing fluid by the application of fire or heat, which explained the name. In the Code of Justinian, the making of it for common uses, or by common persons, was prohibited under penalty of death and confiscation of goods.
It denoted a kind of painting practised by the ancients, in which the crayon was dipped in wax of various colours. Encausto pingere is to practise this art, paint in encaustic or enamel. Encaustum afterwards came to signify an ink for the purpose of writing; and the "sacred encaustum" of Justinian's Code was an ink which the Roman Emperors used for imperial subscriptions. It was of the imperial colour, reddish purple, and was made of the purple dye, prepared in some way by the application of fire. (So that in this use of the word, the notion of burning which there is in the etymology, is still retained.) [from footnote in "The Life, Letters, and Sermons of Bishop Herbert de Losinga," Oxford, 1878]
The usual words for "ink" in Latin was atramentum (source of Old French arrement), literally "anything that serves to dye black," from ater "black;" the Greek word was melan, neuter of melas "black." The Old English word for it was blæc, literally "black," and compare Swedish bläck, Danish blæk "ink." Spanish and Portuguese (tinta) and German (tinte) get their "ink" words from Latin tinctus "a dyeing."
Donkin credits a Greek pronunciation, with the accent at the front of the word, for the French evolution; the same Latin word, behaving regularly, became inchiostro (with unetymological -r-) in Italian, encausto in Spanish. As an adjective, inken (c. 1600) occasionally has been used. Ink-slinger, contemptuous for "journalist," is from 1870. The psychologist's ink-blot test attested from 1915.
mid-14c., "generous," also "nobly born, noble, free;" from late 14c. as "selfless, magnanimous, admirable;" from early 15c. in a bad sense, "extravagant, unrestrained," from Old French liberal "befitting free people; noble, generous; willing, zealous" (12c.), and directly from Latin liberalis "noble, gracious, munificent, generous," literally "of freedom, pertaining to or befitting a free person," from liber "free, unrestricted, unimpeded; unbridled, unchecked, licentious."
This is conjectured to be from PIE *leudh-ero-, which probably originally meant "belonging to the people," though the precise semantic development is obscure; but compare frank (adj.). This was a suffixed form of the base *leudh- (2) "people" (source also of Old Church Slavonic ljudu, Lithuanian liaudis, Old English leod, German Leute "nation, people;" Old High German liut "person, people").
Who hath indeed, most like a liberal villain,
Confess'd the vile encounters they have had
A thousand times in secret.
["Much Ado," IV.1.93]
Liberal was used 16c.-17c. as a term of reproach with the meaning "free from restraint in speech or action." The Enlightenment revived it in a positive sense "free from prejudice, tolerant, not bigoted or narrow," which emerged 1776-88. In 19c. often theological rather than political, opposed to orthodox, used of Unitarians, Universalists, etc. For educational use, see liberal arts.
Purely in reference to political opinion, "tending in favor of freedom and democracy," it dates from c. 1801, from French libéral. In English the label at first was applied by opponents (often in the French form and with suggestions of foreign lawlessness) to the party more favorable to individual political freedoms. But also (especially in U.S. politics) tending to mean "favorable to government action to effect social change," which seems at times to draw more from the religious sense of "free from prejudice in favor of traditional opinions and established institutions" (and thus open to new ideas and plans of reform), which dates from 1823.
This is the attitude of mind which has come to be known as liberal. It implies vigorous convictions, tolerance for the opinions of others, and a persistent desire for sound progress. It is a method of approach which has played a notable and constructive part in our history, and which merits a thorough trial today in the attack on our absorbingly interesting American task. [Guy Emerson, "The New Frontier," 1920]
1560s, "sweet potato," from Spanish patata, from a Carib language of Haiti batata "sweet potato." Sweet potatoes were first to be introduced to Europe; they were in cultivation in Spain by mid-16c. and in Virginia by 1648. Early 16c. Portuguese traders carried the crop to all their shipping ports and the sweet potato was quickly adopted from Africa to India and Java.
"This was the original application of the name, and it is in this sense that the word is generally to be understood when used by English writers down to the middle of the seventeenth century" [Century Dictionary].
The name later (1590s) was extended (based on general likeness, both being esculent tubers) to the common white potato, native to Peru, which was at first (mistakenly) called Virginia potato, or, because at first it was of minor importance compared to the sweet potato, bastard potato. Spanish invaders in Peru began to use white potatoes as cheap food for sailors 1530s.
The first potato from South America reached Pope Paul III in 1540; it was grown in France at first as an ornamental plant. According to popular tradition, it was introduced to Ireland 1565 by John Hawkins. It was brought to England from Colombia by Sir Thomas Herriot, 1586.
German Kartoffel (17c.) is a dissimilation from tartoffel, ultimately from Italian tartufolo (Vulgar Latin *territuberem), originally "truffle." Frederick II forced its cultivation on Prussian peasants in 1743. The French is pomme de terre, literally "earth-apple;" a Swedish dialectal word for "potato" is jordpäron, literally "earth-pear."
Colloquial pronunciation tater is attested in print from 1759. Potato salad is by 1842 as a typical German dish; by 1844 in English cookery books. For Potato chip see chip (n.1); for the British alternative potato crisp see crisp (adj.). Slang potato trap "mouth" is attested from 1785. The Potato Famine in Ireland from 1845 to 1849 was so called by 1851, mostly outside Ireland; in it it is typically the Great Famine, Great Hunger, or Great Starvation.
To drop (something) like a hot potato is from 1824. Children's counting-out rhyme that begins one potato, two potato is recorded by 1885 in Canada.
popular name of a common bird of Europe, Asia, and America, known for its chattering, acquisitiveness, curiosity, and mimicry, c. 1600, earlier simply pie (mid-13c.).
The first element is Mag, nickname for Margaret, long used in proverbial and slang English for qualities associated generally with women, especially in this case "idle chattering" (as in Magge tales "tall tales, nonsense," early 15c.; also compare French margot "magpie," from Margot, pet form of Marguerite). The name Margaret, and its reduced forms Mag, Madge, diminutive Maggie, also has long been familiarly applied to birds. Pies were proverbial since Middle English for chattering (as were jays), hence the application of pie to a prattling gossip or tattler, also "sly person, informer" (late 14c.) and in 15c.-16c. a wily pie (or wyly pye) was "a cunning person."
The second element, pie, is the earlier name of the bird, from Old French pie, from Latin pica "magpie" (source also of Spanish pega), fem. of picus "woodpecker," from PIE root *(s)peik- "woodpecker, magpie" (source also of Umbrian peica "magpie," Sanskrit pikah "Indian cuckoo," Old Norse spætr, German Specht "woodpecker"); possibly from PIE root *pi-, denoting pointedness, of the beak. The application to pies might be because the magpie also has a long, pointed tail.
The birds are proverbial for pilfering and hoarding and for their indiscriminate appetites (see pica (n.2)); they can be taught to speak, and have been regarded since the Middle Ages as ill omens.
Whan pyes chatter vpon a house it is a sygne of ryghte euyll tydynges. 
Divination by numbering magpies is attested from c. 1780 in Lincolnshire; the rhyme varies from place to place, the only consistency being that one is bad, two are good.
The councils which magpies appear to hold together, at particular seasons, commonly called "folkmotes," are associated in the minds of many with superstitious and ominous notions. The innocent objects of terror, while meeting together most probably for the purpose of choosing mates, are supposed to be conspiring and clubbing their wits, for the weal or woe of the inhabitants of the neighbouring village. If they are of an even number and carry on their cheerful, noisy chatter, it is supposed to betoken good to old and young—but if there is an odd magpie perched apart from the rest, silent, and disconsolate, the reverse of this is apprehended, and mischievous consequences are inevitably expected. [The Saturday Magazine, Jan. 23, 1841]
mid-14c., "fluid or juice of an animal or plant," from Old North French humour "liquid, dampness; (medical) humor" (Old French humor, umor; Modern French humeur), from Latin umor "body fluid" (also humor, by false association with humus "earth"); related to umere "be wet, moist," and to uvescere "become wet" (see humid).
In old medicine, "any of the four body fluids" (blood, phlegm, choler, and melancholy or black bile).
The human body had four humors—blood, phlegm, yellow bile, and black bile—which, in turn, were associated with particular organs. Blood came from the heart, phlegm from the brain, yellow bile from the liver, and black bile from the spleen. Galen and Avicenna attributed certain elemental qualities to each humor. Blood was hot and moist, like air; phlegm was cold and moist, like water; yellow bile was hot and dry, like fire; and black bile was cold and dry, like earth. In effect, the human body was a microcosm of the larger world. [Robert S. Gottfried, "The Black Death," 1983]
Their relative proportions were thought to determine physical condition and state of mind. This gave humor an extended sense of "mood, temporary state of mind" (recorded from 1520s); the sense of "amusing quality, funniness, jocular turn of mind" is first recorded 1680s, probably via sense of "whim, caprice" as determined by state of mind (1560s), which also produced the verb sense of "indulge (someone's) fancy or disposition." Modern French has them as doublets: humeur "disposition, mood, whim;" humour "humor." "The pronunciation of the initial h is only of recent date, and is sometimes omitted ..." [OED].
For aid in distinguishing the various devices that tend to be grouped under "humor," this guide, from Henry W. Fowler ["Modern English Usage," 1926] may be of use:
HUMOR: motive/aim: discovery; province: human nature; method/means: observation; audience: the sympathetic
WIT: motive/aim: throwing light; province: words & ideas; method/means: surprise; audience: the intelligent
SATIRE: motive/aim: amendment; province: morals & manners; method/means: accentuation; audience: the self-satisfied
SARCASM: motive/aim: inflicting pain; province: faults & foibles; method/means: inversion; audience: victim & bystander
INVECTIVE: motive/aim: discredit; province: misconduct; method/means: direct statement; audience: the public
IRONY: motive/aim: exclusiveness; province: statement of facts; method/means: mystification; audience: an inner circle
CYNICISM: motive/aim: self-justification; province: morals; method/means: exposure of nakedness; audience: the respectable
SARDONIC: motive/aim: self-relief; province: adversity; method/means: pessimism; audience: the self
Old English understandan "to comprehend, grasp the idea of, receive from a word or words or from a sign the idea it is intended to convey; to view in a certain way," probably literally "stand in the midst of," from under + standan "to stand" (see stand (v.)).
If this is the meaning, the under is not the usual word meaning "beneath," but from Old English under, from PIE *nter- "between, among" (source also of Sanskrit antar "among, between," Latin inter "between, among," Greek entera "intestines;" see inter-). Related: Understood; understanding.
That is the suggestion in Barnhart, but other sources regard the "among, between, before, in the presence of" sense of Old English prefix and preposition under as other meanings of the same word. "Among" seems to be the sense in many Old English compounds that resemble understand, such as underniman "to receive," undersecan "examine, investigate, scrutinize" (literally "underseek"), underðencan "consider, change one's mind," underginnan "to begin."
It also seems to be the sense still in expressions such as under such circumstances. Perhaps the ultimate sense is "be close to;" compare Greek epistamai "I know how, I know," literally "I stand upon."
Similar formations are found in Old Frisian (understonda), Middle Danish (understande), while other Germanic languages use compounds meaning "stand before" (German verstehen, represented in Old English by forstanden "understand," also "oppose, withstand"). For this concept, most Indo-European languages use figurative extensions of compounds that literally mean "put together," or "separate," or "take, grasp" (see comprehend).
The range of spellings of understand in Middle English (understont, understounde, unþurstonde, onderstonde, hunderstonde, oundyrston, wonderstande, urdenstonden, etc.) perhaps reflects early confusion over the elements of the compound. Old English oferstandan, Middle English overstonden, literally "over-stand" seem to have been used only in literal senses.
By mid-14c. as "to take as meant or implied (though not expressed); imply; infer; assume; take for granted." The intransitive sense of "have the use of the intellectual faculties; be an intelligent and conscious being" also is in late Old English. In Middle English also "reflect, muse, be thoughtful; imagine; be suspicious of; pay attention, take note; strive for; plan, intend; conceive (a child)." Also sometimes literal, "to occupy space at a lower level" (late 14c.) and, figuratively, "to submit." For "to stand under" in a physical sense, Old English had undergestandan.
fourteenth letter of the English alphabet; in chemistry, the symbol for nitrogen.
In late Middle English a and an commonly were joined to the following noun, if that word began with a vowel, which caused confusion over how such words ought to be divided when written separately. In nickname, newt, and British dialectal naunt, the -n- belongs to a preceding indefinite article an or possessive pronoun mine.
Other examples of this from Middle English manuscripts include a neilond ("an island," early 13c.), a narawe ("an arrow," c. 1400), a nox ("an ox," c. 1400), a noke ("an oak," early 15c.), a nappyle ("an apple," early 15c.), a negge ("an egg," 15c.), a nynche ("an inch," c. 1400), a nostryche ("an ostrich," c. 1500). My naunt for mine aunt is recorded from 13c.-17c. None other could be no noder (mid-15c.). My nown (for mine own) was frequent 15c.-18c. In 16c., an idiot sometimes became a nidiot (1530s), which, with still-common casual pronunciation, became nidget (1570s), now, alas, no longer whinnying with us.
It is "of constant recurrence" in the 15c. vocabularies, according to Thomas Wright, their modern editor. One has, among many others, Hoc alphabetum ... a nabse, from misdivision of an ABC (and pronouncing it as a word), and Hic culus ... a ners. Also compare nonce, pigsney. Even in 19c. provincial English and U.S., noration (from an oration) was "a speech; a rumor."
The process also worked in surnames, from oblique cases of Old English at "by, near," as in Nock/Nokes/Noaks from atten Oke "by the oak;" Nye from atten ye "near the lowland;" and see Nashville. (Elision of the vowel of the definite article also took place and was standard in Chancery English of the 15c.: þarchebisshop for "the archbishop," thorient for "the orient.")
But it is more common for an English word to lose an -n- to a preceding a: apron, auger, adder, umpire, humble pie, etc. By a related error in Elizabethan English, natomy or atomy was common for anatomy, noyance (annoyance) and noying (adj.) turn up 14c.-17c., and Marlowe (1590) has Natolian for Anatolian. The tendency is not limited to English: compare Luxor, jade (n.1), lute, omelet, and Modern Greek mera for hēmera, the first syllable being confused with the article.
The mathematical use of n for "an indefinite number" is attested by 1717 in phrases such as to the nth power (see nth). In Middle English n. was written in form documents to indicate an unspecified name of a person to be supplied by the speaker or reader.
"artificial penis used for female gratification," 1590s, a word of unknown origin. Traditional guesses include a corruption of Italian deletto "delight" (from Latin dilectio, noun of action from diligere "to esteem highly, to love;" see diligence) or a corruption of English diddle. None of these seems very convincing (Florio's dictionary glosses many words with dildo, but diletto is not one of them.) Century Dictionary perhaps gets closer to the mark:
A term of obscure cant or slang origin, used in old ballads and plays as a mere refrain or nonsense-word; also used, from its vagueness, as a substitute for various obscene terms and in various obscene meanings. 
The earliest use of the word in this sense, and probably the start of its popularity, seems to be via Nashe:
"Curse Eunuke dilldo, senceless counterfet" ["Choise of Valentines or the Merie Ballad of Nash his Dildo," T. Nashe, c. 1593]
Other early forms include dildoides (1675), dildidoes (1607). Middle English had dillidoun (n.) "a darling, a pet" (mid-15c.), from Old Norse dilla "to lull" (hence dillindo "lullaby"). That sense probably survived into Elizabethan times, if it is the word in Jonson's "Cynthia's Revels":
Chorus: Good Mercury defend vs.
Phan.: From perfum'd Dogs, Monkeys, Sparrowes, Dildos, and Parachitos.
And dildin seems to be a term for "sweetheart" in a 1675 play:
Mir.: Here comes a lusty Wooer, my dildin, my darling.
Here comes a lusty Wooer Lady bright and shining.
The thing itself is older. A classical Latin word for one was fascinum (see fascinate). In later English sometimes a French word, godemiché, was used (1879). Also used in 18c. of things that resemble dildoes, e.g. dildo pear (1756), dildo cactus (1792).
Shakespeare plays on the double sense, sexual toy and ballad refrain, in "A Winter's Tale."
SERVANT: He hath songs for man or woman, of all sizes; no
milliner can so fit his customers with gloves: he
has the prettiest love-songs for maids; so without
bawdry, which is strange; with such delicate
burthens of dildos and fadings, 'jump her and thump
her;' and where some stretch-mouthed rascal would,
as it were, mean mischief and break a foul gap into
the matter, he makes the maid to answer 'Whoop, do me
no harm, good man;' puts him off, slights him, with
'Whoop, do me no harm, good man.'