1580s, "advance, proceed," from go (v.) + on (adv.). Meaning "behave, carry on" is from 1777; especially "to talk volubly" (1863). As an expression of derision by 1886.

1909, "with one side facing," from side (n.) + on (adv.), perhaps based on earlier head-on. In reference to a vehicle collision, by 1828.

"craving, longing, strong desire," 1796 [Grose], perhaps a back-formation from lecher, or deformed from a figurative use of latch (v.) in a secondary sense of "grasp, grasp on to." Or perhaps from letch (v.), a variant of leach.

1640s, from un- (2) "reverse, opposite of" + latch (v.).

mid-14c., "iron cross-bar of a window," from Old French loquet "door-handle, bolt, latch, fastening" (14c.), diminutive of loc "lock, latch," from Frankish or some other Germanic source (compare Old Norse lok "fastening, lock;" see lock (n.1)). Meaning "little ornamental case with hinged cover" (containing a lock of hair, miniature portrait, etc.) first recorded 1670s. Italian lucchetto also is from Germanic.

past tense and past participle of catch (v.), attested from 14c., predominant after c. 1800, replacing earlier catched. A rare instance of an English strong verb with a French origin. This might have been by influence of Middle English lacchen (see latch (v.)), which also then meant "to catch" and was more or less a synonym of catch (as their noun forms remain), and which then had past tense forms lahte, lauhte, laught. The influence would have happened before latch switched to its modern weak conjugation.

1731, "pronounce with an accent," from Medieval Latin accentuatus, past participle of accentuare "to accent," from Latin accentus "song added to speech," from ad "to" (see ad-) + cantus "a singing," past participle of canere "to sing" (from PIE root *kan- "to sing"). Figurative meaning "emphasize, place an accent or emphasis on" is recorded from 1865.

You've got to accentuate the positive

Eliminate the negative

Latch on to the affirmative

Don't mess with Mister In-Between

["Ac-Cent-Tchu-Ate the Positive," 1944, music by Harold Arlen, lyrics by Johnny Mercer]

Related: Accentuated; accentuating.

mid-14c., "a kind of door latch," and said to be still the name for rings for raising thumb-latches in the north of England. It appears to be what it looks like: what you say when you open the door ("have good day," as in the 1414 record of them as hafgooddays).

"strap or thong of a sandal or shoe," late 14c., lachet, from Old French lachet, variant of lacet, diminutive of las, laz "noose, string, cord, tie" (see lace (n.)). Spelling altered perhaps by influence of latch.

1845, among some American native peoples, "a gift," from Chinook jargon pot-latch, "a gift," from Nootka (Wakashan) patshatl "giving, gift." Later (1865) in sense "An Indian feast, often lasting several days, given to the tribe by a member who aspires to the position of chief, and whose reputation is estimated by the number and value of the gifts distributed at the feast" [Century Dictionary, 1895]