c.1200, "to watch with hostile intent, lie in wait for," from Old North French waitier "to watch" (Old French gaitier, Modern French guetter), from Frankish *wahton (cf. Dutch wacht "a watching," Old High German wahten, German wachten "to watch, to guard;" Old High German wahhon "to watch, be awake," Old English wacian "to be awake;" see wake (v.)). General sense of "remain in some place" is from late 14c.; that of "to see to it that something occurs" is late 14c. Meaning "to stand by in attendance on" is late 14c.; specific sense of "serve as an attendant at a table" is from 1560s. Related: Waited; waiting.
To wait (something) out "endure a period of waiting" is recorded from 1909, originally American English, in reference to baseball batters trying to draw a base on balls. Waiting game is recorded from 1890. Waiting room is attested from 1680s. Waiting list is recorded from 1897; the verb wait-list "to put (someone) on a waiting list" is recorded from 1960.
early 13c., "a watcher, onlooker," from Old North French wait, Old French gaite, from gaitier (see wait (v.)). From late 14c. as "an ambush, a trap" (as in lie in wait).