1560s, "A solid generated by the revolution of a right-angled triangle upon one of its sides as an axis" [Century Dictionary], from French cone (16c.) or directly from Latin conus "a cone, peak of a helmet," from Greek konos "cone, spinning top, pine cone," which is perhaps from a PIE root *ko- "to sharpen" (source also of Sanskrit sanah "whetstone," Latin catus "sharp," Old English han "stone"), but Beekes considers it likely a Pre-Greek word.

There is a use from c. 1400 as "angle or corner of a quadrant," from Latin. From 1560s as "dry, cone-shaped fruit of the pine;" from 1771 as "hill surrounding the crater of a volcano; 1867 as "minute structure in the retina of the eye;" by 1909 as "a conical wafer to hold ice-cream." Cone-shell is from 1770, so called for its shape; cone-flower is from 1822, so called for its conical receptacles.

Probably the greatest "rage" of the year in the eating line has been the ice cream cone. The craze has known no section, although the Middle West has eaten more than any other section, and the South has yet to acquire the habit. As a result of this craze hundreds of cone factories have sprung up, and every one has made large profits. Thus an important side line has come to the fore in aid of the ice cream industry. [The Ice Cream Trade Journal, October 1909]

"insincere, trifling, or deceptive talk," 1914. Popularly associated with roughly contemporary bullshit (n.) in the same sense, and in modern use often felt as a shortened form of it. There seems to have been an identical Middle English word meaning "false talk, fraud," apparently from Old French bole "deception, trick, scheming, intrigue," and perhaps related to modern Icelandic bull "nonsense."

Sais christ to ypocrites ... yee ar ... al ful wit wickednes, tresun, and bull. ["Cursor Mundi," Northumbrian, early 14c.]

There also was an early Modern English verb bull meaning "to mock, cheat," which dates from 1530s. Bull session is attested from 1920.

Also uncertain is the relationship to the bull that means "a gross inconsistency in language, a ludicrous blunder involving a contradiction in terms" (1630s), said by the English to be characteristic of the Irish, and thus often called an Irish bull. Sydney Smith defined it as "an apparent congruity, and real incongruity of ideas, suddenly discovered." Three examples attributed to Sir Boyle Roche: "Why should we do anything for posterity, for what, in the name of goodness, has posterity done for us?" ... "It would surely be better, Mr. Speaker, to give up not only a part, but, if necessary, even the whole of our Constitution, to preserve the remainder." ... "The best way to avoid danger is to meet it plump."

"an ice-skate, a contrivance for enabling a person to glide swiftly on ice," 1660s, skeates (plural), from Dutch schaats (plural schaatsen), a singular mistaken in English for plural, from Middle Dutch schaetse. The word and the custom were brought to England after the Restoration by exiled followers of Charles II who had taken refuge in Holland.

The Dutch word is perhaps from Old North French escache "a stilt, trestle," related to Old French eschace "stilt" (French échasse), from Frankish *skakkja "stilt" or a similar Germanic source (compare Frisian skatja "stilt"), perhaps literally "thing that shakes or moves fast" and related to root of Old English sceacan "to vibrate" (see shake (v.)). Or perhaps [Klein] the Dutch word is connected to Middle Low German schenke, Old English scanca "leg" (see shank). If the former, the sense alteration in Dutch from "stilt" to "skate" is not clearly traced. The latter theory perhaps is supported by evidence that the original ice skates, up to medieval times, were leg bones of horse, ox, or deer, strapped to the feet with leather strips.

The sense in English was extended to roller-skates by 1876. The meaning "an act of skating" is from 1853. A slightly older word for an ice skate was scrick-shoe (1650s), from Middle Dutch scricschoe, from schricken "to slide." 

Old English hond, hand "the human hand;" also "side, part, direction" (in defining position, to either right or left); also "power, control, possession" (on the notion of the hand's grip or hold), from Proto-Germanic *handuz (source also of Old Saxon, Old Frisian, Dutch, German hand, Old Norse hönd, Gothic handus), which is of uncertain origin.

The original Old English plural handa was superseded in Middle English by handen, later hands. Indo-European "hand" words tend to be from roots meaning "seize, take, collect" or are extended from words originally meaning only a part of the hand (such as Irish lam, Welsh llaw, cognate with Latin palma and originally meaning "palm of the hand"). One ancient root (*man- (2)), represented by Latin manus is the source of Old English mund "hand," but more usually meaning "protection, guardianship; a protector, guardian."

Meaning "manual worker, person who does something with his hands" is from 1580s, hence "hired workman" (1630s) and "sailor in a ship's crew" (1660s). Meaning "agency, part in doing something" is from 1590s. Clock and watch sense is from 1570s. Meaning "round of applause" is from 1838. The linear measure of 4 inches (originally 3) is from 1560s, now used only in giving the height of horses. The meaning "playing cards held in one player's hand" is from 1620s; that of "a round at a card game" is from 1620s. Meaning "handwriting" is from late 14c.; also "one's style of penmanship" (early 15c.). The word in reference to the various uses of hands in making a pledge is by c. 1200; specifically "one's pledge of marriage" by late 14c.

First hand, second hand, etc. (mid-15c.) are from the notion of something being passed from hand to hand. At hand is from c. 1200 as "near in time," c. 1300 as "within reach." Out of hand (1590s) is opposite of in hand "under control" (c. 1200). Adverbial phrase hand-over-fist (1803) is nautical, suggestive of hauling or climbing by passing the hands one before the other alternately.

Phrase on the one hand ... on the other hand is recorded from 1630s, a figurative use of the physical sense of hand in reference to position on one side or the other side of the body (as in the lefthand side), which goes back to Old English Hands up! as a command from a policeman, robber, etc., is from 1863, from the image of holding up one's hands as a token of submission or non-resistance. Hand-to-hand "in close contact," of fighting, is from c. 1400. Hand-to-mouth "said of a person who spends his money as fast as he gets it, who earns just enough to live on from day to day" [Bartlett] is from c. 1500. Hand-in-hand attested from c. 1500 as "with hands clasped;" figurative sense of "concurrently" recorded from 1570s.

"receptacle, box, that which encloses or contains," early 14c., from Anglo-French and Old North French casse (Old French chasse "case, reliquary;" Modern French châsse), from Latin capsa "box, repository" (especially for books), from capere "to take, hold" (from PIE root *kap- "to grasp").

The meaning "outer protective covering" is from late 14c. Also used from 1660s with a sense of "frame" (as in staircase, casement). Artillery sense is from 1660s, from case-shot "small projectiles put in cases" (1620s). Its application in the printing trade (first recorded 1580s) to the two shallow wooden trays where compositors keep their types in compartments for easy access led to upper-case for capital letters (1862), so called from its higher position on the compositor's sloped work-table, and lower-case for small letters.

The cases, or receptacles, for the type, which are always in pairs, and termed the 'upper' and the 'lower,' are formed of two oblong wooden frames, divided into compartments or boxes of different dimensions, the upper case containing ninety-eight and the lower fifty-four. In the upper case are placed the capital, small capital, and accented letters, also figures, signs for reference to notes &c.; in the lower case the ordinary running letter, points for punctuation, spaces for separating the words, and quadrats for filling up the short lines. [The Literary Gazette, Jan. 29, 1859]

"1 more than nine, twice five; the number which is one more than nine; a symbol representing this number;" Old English ten (Mercian), tien (West Saxon), adjective and noun, from Proto-Germanic *tehun (source also of Old Saxon tehan, Old Norse tiu, Danish ti, Old Frisian tian, Old Dutch ten, Dutch tien, Old High German zehan, German zehn, Gothic taihun "ten"), from PIE root *dekm- "ten."

Meaning "ten o'clock" is from 1712. Tenner "ten-pound note" is slang first recorded 1861; as "ten-dollar bill," 1887 (ten-spot in this sense dates from 1848). The Texan's exaggerated ten-gallon hat is from 1919. The ten-foot pole that you wouldn't touch something with (1909) was originally a 40-foot pole; the notion is of keeping one's distance, as in the advice to use a long spoon when you dine with the devil.

From thirty feet away she looked like a lot of class. From ten feet away she looked like something made up to be seen from thirty feet away. [Raymond Chandler, "The High Window," 1942] 

Ten-four "I understand, message received," is attested in popular jargon from 1962, from citizens band and emergency dispatch radio 10-code (in use in U.S. by 1950).

c. 1300, "invisible gases that surround the earth," from Old French air "atmosphere, breeze, weather" (12c.), from Latin aer "air, lower atmosphere, sky," from Greek aēr (genitive aeros) "mist, haze, clouds," later "atmosphere" (perhaps related to aenai "to blow, breathe"), which is of unknown origin. It is possibly from a PIE *awer- and thus related to aeirein "to raise" and arteria "windpipe, artery" (see aorta) on notion of "lifting, suspended, that which rises," but this has phonetic difficulties.

In Homer mostly "thick air, mist;" later "air" as one of the four elements. Words for "air" in Indo-European languages tend to be associated with wind, brightness, sky. In English, air replaced native lyft, luft (see loft (n.)). In old chemistry, air (with a qualifying adjective) was used of any gas.

To be in the air "in general awareness" is from 1875; up in the air "uncertain, doubtful" is from 1752. To build castles in the air "entertain visionary schemes that have no practical foundation" is from 1590s (in 17c. English had airmonger "one preoccupied with visionary projects"). Broadcasting sense (as in on the air, airplay) is by 1927. To give (someone) the air "dismiss" is from 1900. Air pollution is attested by 1870. Air guitar is by 1983. Air traffic controller is from 1956.

greeting between persons meeting, 1848, early references are to the U.S. western frontier (where hello, the house was said to be the usual greeting upon approaching a habitation).

It is an alteration of hallo, itself an alteration of holla, hollo, a shout to attract attention, which seems to go back at least to late 14c. (compare Middle English verb halouen "to shout in the chase," hallouing). OED cites Old High German hala, hola, emphatic imperative of halon, holon "to fetch," "used especially in hailing a ferryman." Fowler in the 1920s listed halloo, hallo, halloa, halloo, hello, hillo, hilloa, holla, holler, hollo, holloa, hollow, hullo, and writes, "The multiplicity of forms is bewildering ...."

Its rise to popularity as a greeting (1880s) coincides with the spread of the telephone, where it won out as the word said in answering, over Alexander Graham Bell's suggestion, ahoy. Central telephone exchange operators were known as hello-girls (1889).

Hello, formerly an Americanism, is now nearly as common as hullo in Britain (Say who you are; do not just say 'hello' is the warning given in our telephone directories) and the Englishman cannot be expected to give up the right to say hello if he likes it better than his native hullo. [H.W. Fowler, "A Dictionary of Modern English Usage," 1926]

Old English beste, reduced by assimilation of -t- from earlier Old English betst "of the highest quality or standing, first, in the best manner." This originally was the superlative of bōt "remedy, reparation" (Middle English bote "advantage, help, profit"), a word now surviving in its simple form only in the expression to boot (see boot (n.2)). Its comparative, better, and superlative, best, have been transferred to good (and in some cases well).

Old English bōt is from Proto-Germanic root *bat-, with comparative *batizon and superlative *batistaz. The superlative form is the source also of Old Frisian, Old Saxon, Middle Dutch best, Old High German bezzist, German best, Old Norse beztr, Gothic batists. Also in Old English as an adverb, "in the most excellent manner."

The best-laid schemes o' mice an' men

     Gang aft agley,

An' lea'e us nought but grief an' pain,

     For promis'd joy!

[Burns, from "To a Mouse, on Turning Her Up in Her Nest With the Plough, November, 1785"]

From late Old English as "of greatest advantage, most suitable." Best-seller as short for "best-selling book" is from 1889, apparently originally in the publishing trade; best friend was in Chaucer (late 14c.). Best girl is attested by 1881, American English; best man is 1814, originally Scottish, replacing groomsman.