Meaning

noun a humble request for help from someone in authority

noun (law) a defendant's answer by a factual matter (as distinguished from a demurrer)

noun an answer indicating why a suit should be dismissed

originFrom Middle English ple, from Old French plait, plaid, from Medieval Latin placitum (“a decree, sentence, suit, plea, etc., Latin an opinion, determination, prescription, order; literally, that which is pleasing, pleasure”), neuter of placitus, past participle of placere (“to please”). Cognate with Spanish pleito (“lawsuit, suit”). Doublet of placit. See also please, pleasure.

Etymology from Wiktionary, CC BY-SA 3.0