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