"mid-day repast, small meal between breakfast and dinner," 1786, a shortened form of luncheon (q.v.) in this sense (1650s), which is of uncertain origin; it appears to be identical with an older word meaning "thick piece, hunk" (1570s), which perhaps evolved from lump (n.) [OED]. There also was a contemporary nuncheon "light mid-day meal," from noon + Middle English schench "drink." Old English had nonmete "afternoon meal," literally "noon-meat" (Middle English non-mete). The verb meaning "to take to lunch" (said to be from the noun) also is attested from 1786:
PRATTLE. I always to be ſure, makes a point to keep up the dignity of the family I lives in. Wou'd you take a more ſolid refreſhment?—Have you lunch'd, Mr. Bribe?
BRIBE. Lunch'd O dear! Permit me, my dear Mrs. Prattle, to refreſh my sponge, upon the honey dew that clings to your raviſhing pouters. O! Mrs. Prattle, this ſhall be my lunch. (kiſſes)
["The Mode," in William Davies' "Plays Written for a Private Theatre," London, 1786]
As late as 1817 the only definition of lunch (n.) in Webster's is "a large piece of food," but this is now obsolete or provincial. OED says in 1820s the word "was regarded either as a vulgarism or as a fashionable affectation." Related: Lunched; lunching.
Lunch money is attested from 1868. Lunch-time is from 1821; lunch hour is from 1840; lunch-break is from 1960. Slang phrase out to lunch "insane, stupid, clueless" first recorded 1955, on notion of being "not there."
box n.1
"rectangular wooden container," usually with a lid, Old English box, also the name of a type of shrub, from Late Latin buxis, from Greek pyxis "boxwood," pyxion "writing table, box," made of boxwood, from pyxos "box tree," which is of uncertain origin. Beekes suggests a loan-word from Italy, as that is where the tree is native. Dutch bus, German Büchse "box; barrel of a gun," also are Latin loan-words.
The meaning "compartment at a theater" is from c. 1600 (box seat in the theatrical sense is by 1850). The meaning "pigeon-hole at a post office" is from 1832. The meaning "television" is from 1950 (earlier "gramophone player," 1924). The meaning "station of a player in baseball" is from 1881. The graphics sense of "space enclosed within borders and rules" is from 1929. The slang meaning "vulva" is attested 17c., according to "Dictionary of American Slang;" modern use seems to date from c. World War II, perhaps originally Australian, on the notion of box of tricks. Box lunch (n.) is attested from 1899. The box set "multiple-album, CD or cassette issue of the work of an artist" is attested by 1955. To think or act outside the box "contrary to convention" is attested by 1994.
lunch-pail n.
"pail such as working men used to carry their lunches to job sites," by 1811, from lunch (n.) + pail (n.). As an adjective, indicating working-class men or values, by 1990s, also lunch-bucket (1873 in the literal se4nse). Compare lunch-box (1864); lunch-basket (1840).