1860, "to remain clinging," 1860, especially "cling fondly to" (1871); see hang (v.) + on (adv.). As a command to be patient, wait a minute, from 1936, originally in telephone conversations.

1640s, "continue to advance," also "manage, be engaged in," from carry (v.) + on (adv.). The meaning "conduct oneself in a wild and thoughtless manner" is by 1828. Carryings-on is from 1660s as "questionable doings," from 1866 as "riotous behavior." As an adjective, carry-on, in reference to luggage that may be brought into the passenger compartment of an airliner, is attested by 1965.

1590s, "to put on," from get (v.) + on (adv.). Meaning "prosper" is from 1785; that of "to advance, make progress" is from 1798; that of "be friendly" (with) is attested by 1816.

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.

1726, in on the qui vive "on the alert," from French être sur le qui vive "be on the alert," from the phrase qui voulez-vous qui vive? sentinel's challenge, "whom do you wish to live?" In other words "(long) live who?" meaning "whose side are you on?" (The answer might be Vive la France, Vive le roi, etc.). From qui (from Latin qui "who") + vive, third person singular present subjunctive of vivre, from Latin vivere "to live" (see viva).

c. 1300, "droop, descend," from go (v.) + down (adv.). Meaning "decline, fail" is from 1590s. Sense of "to happen" is from 1946, American-English slang. Go down on "perform oral sex on" is from 1916.

1779, French, literally "on the way" (see route (n.)).

1963, from French tiers monde, formulated 1952 by French economic historian Alfred Sauvy (1898-1990) on model of the third estate (French tiers état) of Revolutionary France; his first world (The West) and second world (the Soviet bloc) never caught on.

verbal phrase; see set (v.) + off (adv.). From 1590s as "make prominent by contrast," 1610s as "adorn." Intransitive sense of "start on or as on a journey" is from 1774. Meaning "separate from contect" (in typography) is from 1824; sense of "ignite, discharge, cause to explode" is from 1810.

"small Central American state with an economy dependent on banana production," 1901, American English.