Yours, Etc.: Origins and Uses of 8 Sign-Offs
c.1400, capcyus, from Middle French captieux (15c.) or directly from Latin captiosus "fallacious," from captionem (nominative captio) "a deceiving, fallacious argument," literally "a taking (in)," from captus, past participle of capere "to take, catch" (see capable). Related: Captiously; captiousness.