1540s, from Latin acclamationem (nominative acclamatio) "a calling, exclamation, shout of approval," noun of action from past participle stem of acclamare "shout approval or disapproval of, cry out at," from ad- "toward" (see ad-) + clamare "cry out" (see claim (v.)). As a method of voting en masse, by 1801, probably from the French Revolution.
