Word Origin & History
early 14c., "to be agreeable," from O.Fr. plaisir (Fr. plaire) "to please," from L. placere "to be acceptable, be liked, be approved," related to placare "to soothe, quiet," from PIE base *p(e)lag- "to smooth, make even" (cf. Gk. plax, gen. plakos "level surface," plakoeis "flat;" Lett. plakt "to become
flat;" O.N. flaga "layer of earth;" Norw. flag "open sea;" O.E. floh "piece of stone, fragment;" O.H.G. fluoh "cliff"). Intransitive sense (e.g. do as you please) first recorded c.1500; imperative use (e.g. please do this), first recorded 1620s, was probably a shortening of if it please (you) (late 14c.). Verbs for "please" supply the stereotype polite word ("Please come in," short for may it please you to ...) in many languages (Fr., It.), "But more widespread is the use of the first singular of a verb for 'ask, request' " [Buck, who cites Ger. bitte, Pol. prasze, etc.] Sp. favor is short for hace el favor "do the favor." Danish has in this sense vær saa god, lit. "be so good."