"apt to notice and make much of unimportant faults or flaws," c. 1400, capcyus, 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" (from PIE root *kap- "to grasp"). Related: Captiously; captiousness.
