"expression or round of applause, praise bestowed with audible demonstrations," 1620s, short for plaudite "an actor's request for applause" (1560s), from Latin plaudite! "applaud!" second person plural present imperative of plaudere "to clap, strike, beat; applaud, clap the hands; approve," a word of unknown origin (also in applaud, explode). This was the customary appeal for applause that Roman actors made at the end of a play. In English, the -e went silent then was dropped. Related: Plauditor; plauditory.