1630s, atmosphaera (modern form from 1670s), "gaseous envelop surrounding the earth," from Modern Latin atmosphaera, from Greek atmos "vapor, steam" (see atmo-) + sphaira "sphere" (see sphere). In old science, "vaporous air," which was considered a part of the earth and a contamination of the lower part of the air (n.1).
Þe ouer partye of þe eyr is pure and clene, clere, esy & softe, ffor mevynge of stormys, of wynde and of wedir may nat reche þerto; and so it perteyneþ to heuenlych kynde. And þe neþir partye is nyʒe to þe spere of watir and of erþe, and is troubly, greet and þicke, corpulent and ful of moyst erþy vapoures, as longiþ to erþy partyes. Þe eyr strecchiþ hym kyndely al aboute fro þe ouer partye of þe erþe and of watir anon to þe spere of fire. [Bartholomew Glanville, "De proprietatibus rerum," c. 1240, translated by John of Trevisa c. 1398 ]
First used in English in connection with the Moon, which, as it turns out, practically has none.
'Tis Observed, in the Solary Eclipses, that there is some times a great Trepidation about the Body of the Moon, from which we may likewise argue an Atmo-sphaera, since we cannot well conceive what so probable a cause there should be of such an appearance as this, Quod radii Solares a vaporibus Lunam ambientibus fuerint intercisi, that the Sun-beams were broken and refracted by the Vapours that encompassed the Moon. [Rev. John Wilkins, "Discovery of New World or Discourse tending to prove that it probable there may be another World in the Moon," 1638]
Figurative sense of "surrounding influence, mental or moral environment" is c. 1800.
late 14c., "clearly revealed to the eye or the understanding, open to view or comprehension," from Old French manifest "evident, palpable," (12c.), or directly from Latin manifestus "plainly apprehensible, clear, apparent, evident;" of offenses, "proved by direct evidence;" of offenders, "caught in the act," probably from manus "hand" (from PIE root *man- (2) "hand") + -festus, which apparently is identical to the second element of infest.
De Vaan writes, "If manifestus may be interpreted as 'caught by hand', the meanings seem to point to 'grabbing' or 'attacking' for -festus." But he finds none of the proposed ulterior connections compelling, and concludes that, regarding infestus and manifestus, "maybe the two must be separated." If not, the sense development might be from "caught by hand" to "in hand, palpable."
Manifest destiny, "that which clearly appears destined to come to pass; a future state, condition, or event which can be foreseen with certainty, or is regarded as inevitable" was much used in American politics from about the time of the Mexican War "by those who believed that the United States were destined in time to occupy the entire continent" [Century Dictionary].
Other nations have tried to check ... the fulfillment of our manifest destiny to overspread the Continent allotted by Providence for the free development of our yearly multiplying millions. [John O'Sullivan (1813-1895), "U.S. Magazine & Democratic Review," July 1845]
The phrase apparently is O'Sullivan's coinage; the notion is as old as the republic.
c. 1200, perhaps mid-12c., "well-born man, man of good family or birth," also extended to Roman patricians and ancient Greek aristocrats, from gentle + man (n.); the compound probably is modeled on Old French gentilhomme (the English gentleman itself was borrowed into French in 18c.).
Given specific uses in late Middle English (small gentleman, gentleman-of-arms, gentleman-usher, etc.), hence in England the word often meant any man above the social rank of a yeoman, including the nobility, but it was sometimes restricted to those who bear a coat of arms but not a title; in U.S., "man of property, not engaged in business or a profession" (1789). The English word from the beginning also had a special sense "nobleman whose behavior conforms to the ideals of chivalry and Christianity," and gentleman came to be used loosely for any man of good breeding, courtesy, kindness, honor, strict regard for the feelings of others, etc.
[The Gentleman] is always truthful and sincere ; will not agree for the sake of complaisance or out of weakness ; will not pass over that of which he disapproves. He has a clear soul, and a fearless, straightforward tongue. On the other hand, he is not blunt and rude. His truth is courteous ; his courtesy, truthful ; never a humbug, yet, where he truthfully can, he prefers to say pleasant things. [The Rev. John R. Vernon, "The Grand Old Name of Gentleman," in Contemporary Review, vol. XI, May-August 1869]
Eventually, in polite use, it came to mean a man in general, regardless of social standing. Related: Gentlemen. Gentleman's agreement is first attested 1929. Gentleman farmer recorded from 1749, "A man of means who farms on a large scale, employs hands, and does little or none of the work himself" [Craigie, "Dictionary of American English"].
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.'
1507, "the western hemisphere, North and South America," in Cartographer Martin Waldseemüller's treatise "Cosmographiae Introductio," from Modern Latin Americanus, after Amerigo Vespucci (1454-1512) who made two trips to the New World as a navigator and claimed to have discovered it. His published works put forward the idea that it was a new continent, and he was first to call it Novus Mundus "New World." Amerigo is more easily Latinized than Vespucci (Latin Vesputius, which might have yielded place-name Vesputia). The sense in English naturally was restricted toward the British colonies, then the United States.
The man's name Amerigo is Germanic, said to derive from Gothic Amalrich, literally "work-ruler." The Old English form of the name has come down as surnames Emmerich, Emery, etc. The Italian fem. form merged into Amelia.
Colloquial pronunciation "Ameri-kay," not uncommon 19c., goes back to at least 1643 and a poem that rhymed the word with away. Amerika "U.S. society viewed as racist, fascist, oppressive, etc." is attested from 1969; the spelling is German but may also suggest the KKK.
It is a thousand pities that the puny witticisms of a few professional objectors should have the power to prevent, even for a year, the adoption of a name for our country. At present we have, clearly, none. There should be no hesitation about "Appalachia." In the first place, it is distinctive. "America" is not, and can never be made so. We may legislate as much as we please, and assume for our country whatever name we think right — but to use it will be no name, to any purpose for which a name is needed, unless we can take it away from the regions which employ it at present. South America is "America," and will insist upon remaining so. [Edgar Allan Poe, "Marginalia," in Graham's Magazine, Philadelphia, December 1846]
FREDONIA, FREDONIAN, FREDE, FREDISH, &c. &c. These extraordinary words, which have been deservedly ridiculed here as well as in England, were proposed sometime ago, and countenanced by two or three individuals, as names for the territory and people of the United States. The general term American is now commonly understood (at least in all places where the English language is spoken,) to mean an inhabitant of the United States; and is so employed, except where unusual precision of language is required. [John Pickering, "A Vocabulary, or Collection of Words and Phrases Which Have Been Supposed to be Peculiar to the United States of America," Boston, 1816]
"monetary unit or standard of value in the U.S. and Canada," 1550s, daler, originally in English the name of a large, silver coin of varying value in the German states, from Low German daler, from German taler (1530s, later thaler), abbreviation of Joachimstaler, literally "(gulden) of Joachimstal," coin minted 1519 from silver from mine opened 1516 near Sankt Joachimsthal, town in Erzgebirge Mountains in northwest Bohemia. German Tal is cognate with English dale. The spelling had been modified to dollar by 1600.
The thaler was from 17c. the more-or-less standardized coin of northern Germany (as opposed to the southern gulden). It also served as a currency unit in Denmark and Sweden (and later was a unit of the German monetary union of 1857-73 equal to three marks).
English colonists in America used the word dollar from 1580s in reference to Spanish peso or "piece of eight," also a large silver coin of about the same fineness as the thaler. Due to extensive trade with the Spanish Indies and the proximity of Spanish colonies along the Gulf Coast, the Spanish dollar probably was the coin most familiar in the American colonies and the closest thing to a standard in all of them.
When the Revolution came, it had the added advantage of not being British. It was used in the government's records of public debt and expenditures, and the Continental Congress in 1786 adopted dollar as a unit when it set up the modern U.S. currency system, which was based on the suggestion of Gouverneur Morris (1782) as modified by Thomas Jefferson. None were circulated until 1794.
When William M. Evarts was Secretary of State he accompanied Lord Coleridge on an excursion to Mount Vernon. Coleridge remarked that he had heard it said that Washington, standing on the lawn, could throw a dollar clear across the Potomac. Mr. Evarts explained that a dollar would go further in those days than now. [Walsh]
Phrase dollars to doughnuts "an assured thing, a certainty" (such that one would bet a dollar against a doughnut on it) is attested by 1884; dollar diplomacy "financial imperialism, foreign policy based on financial and commercial interests" is from 1910.
The dollar sign ($) is said to derive from the image of the Pillars of Hercules, stamped with a scroll, on the Spanish piece of eight. However, according to the Bureau of Engraving and Printing of the U.S. Department of the Treasury:
[T]he most widely accepted explanation is that the symbol is the result of evolution, independently in different places, of the Mexican or Spanish "P's" for pesos, or piastres, or pieces of eight. The theory, derived from a study of old manuscripts, is that the "S" gradually came to be written over the "P," developing a close equivalent of the "$" mark. It was widely used before the adoption of the United States dollar in 1785.
Old English wicce "female magician, sorceress," in later use especially "a woman supposed to have dealings with the devil or evil spirits and to be able by their cooperation to perform supernatural acts," fem. of Old English wicca "sorcerer, wizard, man who practices witchcraft or magic," from verb wiccian "to practice witchcraft" (compare Low German wikken, wicken "to use witchcraft," wikker, wicker "soothsayer").
OED says of uncertain origin; Liberman says "None of the proposed etymologies of witch is free from phonetic or semantic difficulties." Klein suggests connection with Old English wigle "divination," and wig, wih "idol." Watkins says the nouns represent a Proto-Germanic *wikkjaz "necromancer" (one who wakes the dead), from PIE *weg-yo-, from PIE root *weg- "to be strong, be lively."
That wicce once had a more specific sense than the later general one of "female magician, sorceress" perhaps is suggested by the presence of other words in Old English describing more specific kinds of magical craft. In the Laws of Ælfred (c. 890), witchcraft was specifically singled out as a woman's craft, whose practitioners were not to be suffered to live among the West Saxons:
Ða fæmnan þe gewuniað onfon gealdorcræftigan & scinlæcan & wiccan, ne læt þu ða libban.
The other two words combined with it here are gealdricge, a woman who practices "incantations," and scinlæce "female wizard, woman magician," from a root meaning "phantom, evil spirit."
Another word that appears in the Anglo-Saxon laws is lyblæca "wizard, sorcerer," but with suggestions of skill in the use of drugs, because the root of the word is lybb "drug, poison, charm" (see leaf (n.)). Lybbestre was a fem. word meaning "sorceress," and lybcorn was the name of a certain medicinal seed (perhaps wild saffron). Weekley notes possible connection to Gothic weihs "holy" and German weihan "consecrate," and writes, "the priests of a suppressed religion naturally become magicians to its successors or opponents." Whatever the English word's origin, the use of a "poisoner" word for "witch, sorceress" parallels that of the Hebrew word used for "witch, sorceress" in the Levitical condemnation.
In Anglo-Saxon glossaries, wicca renders Latin augur (c. 1100), and wicce stands for "pythoness, divinatricem." In the "Three Kings of Cologne" (c. 1400) wicca translates Magi:
Þe paynyms ... cleped þe iij kyngis Magos, þat is to seye wicchis.
The glossary translates Latin necromantia ("demonum invocatio") with galdre, wiccecræft. The Anglo-Saxon poem called "Men's Crafts" (also "The Gifts of Men") has wiccræft, which appears to be the same word, and by its context means "skill with horses." In a c. 1250 translation of "Exodus," witches is used of the Egyptian midwives who save the newborn sons of the Hebrews: "Ðe wicches hidden hem for-ðan, Biforen pharaun nolden he ben."
Witch in reference to a man survived in dialect into 20c., but the fem. form was so dominant by 1601 that men-witches or he-witch began to be used. Extended sense of "old, ugly, and crabbed or malignant woman" is from early 15c; that of "young woman or girl of bewitching aspect or manners" is first recorded 1740. Witch doctor is from 1718; applied to African magicians from 1836.
At this day it is indifferent to say in the English tongue, 'she is a witch,' or 'she is a wise woman.' [Reginald Scot, "The Discoverie of Witchcraft," 1584]
late Old English mægester "a man having control or authority over a place; a teacher or tutor of children," from Latin magister (n.) "chief, head, director, teacher" (source of Old French maistre, French maître, Spanish and Italian maestro, Portuguese mestre, Dutch meester, German Meister), contrastive adjective ("he who is greater") from magis (adv.) "more," from PIE *mag-yos-, comparative of root *meg- "great." The form was influenced in Middle English by Old French cognate maistre.
From late 12c. as "man eminently or perfectly skilled in something," also "one who is chief teacher of another (in religion, philosophy, etc.), religious instructor, spiritual guide." Sense of "master workman or craftsman, workman who is qualified to teach apprentices and carry on a trade on his own account" is from c. 1300. The meaning "one charged with the care, direction, oversight, and control of some office, business, etc." is from mid-13c.; specifically as "official custodian of certain animals kept for sport" early 15c. (maister of þe herte houndes; the phrase master of the hounds is attested by 1708). As a title of the head or presiding officer of an institution, late 14c.; as "captain of a merchant vessel" early 14c.
In the broadest sense, "one who has power to control, use, or dispose (of something or some quality) at will," from mid-14c. Also from mid-14c. as "one who employs another or others in his service" (in which sense the correlative word was servant, man, or apprentice); also "owner of a living creature" (a dog, a horse, also, in ancient contexts a slave); paired with slave in the legal language of the American colonies by 1705 in Virginia.
In academic sense "one who has received a specific degree" (translating Medieval Latin magister) it is attested from mid-13c., originally "one who has received a degree conveying authority to teach in the universities;" master's degree, originally a degree giving one authority to teach in a university, is from late 14c.
Also used in Middle English of dominant women. From 1530s as "male head of a household." As a title or term of respect or rank, mid-14c. As a title prefixed to the name of a young gentleman or boy of the better class not old enough to be called Mr., short for young master (late 16c.). Sense of "chess player of the highest class at national or international level" is by 1894. Meaning "original of a recording" is by 1904.
As an adjective from late 12c. Master-key, one that will open ("master") a number of locks so differently constructed that the key proper to each will open none of the others" is from 1570s. Master race "race of people considered to be pre-eminent in greatness or power" (typical in reference to Nazi theories of the Aryan race, perhaps based on German Herrenvolk) is by 1935. From 1530 as "artist of distinguished skill;" old masters is attested by 1733.
Master bedroom, "bedroom designed for the use of the owner of the property," as opposed to bedrooms for children or guests, is by 1919 in U.S. home-builders publications (e.g. Building Age, April 1919). It seems to be based on the English master's bedroom (by 1903) "bedroom of a headmaster or other master at an English boarding school or other similar institution."
The top floor was treated much the same as the two lower ones. Here the closet was made just a bit larger so as to allow for a bathtub, thus pushing the partition forward, making the front room less deep than the rooms below, yet paradoxically larger, because it takes in the whole front of the house. This is what is known in English advertisements as the "Master's bedroom." [The House Beautiful, June 1921]