mid-15c., appesement, "pacification," from Old French apaisement "appeasement, calming," noun of action from apaisier "pacify, make peace, placate" (see appease). First recorded 1919 in international political sense; not pejorative until the failure of British Prime Minister Neville Chamberlain's policy toward Germany in 1939 (methods of appeasement was Chamberlain's description of his policy).
It forms all or part of: Areopagus; appease; appeasement; compact (adj.) "concentrated;" compact (n.1) "agreement;" fang; impact; impale; impinge; newfangled; pace (prep.) "with the leave of;" pacific; pacify; pact; pagan; page (n.1) "sheet of paper;" pageant; pale (n.) "limit, boundary, restriction;" palette; palisade; patio; pawl; pax; pay; peace; peasant; pectin; peel (n.2) "shovel-shaped instrument;" pole (n.1) "stake;" propagate; propagation; travail; travel.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit pasa- "cord, rope," pajra- "solid, firm;" Avestan pas- "to fetter;" Greek pegnynai "to fix, make firm, fast or solid," pagos "pinnacle, cliff, rocky hill;" Latin pangere "to fix, to fasten," pagina "column," pagus "district;" Slavonic paž "wooden partition;" Old English fegan "to join," fon "to catch seize."
"appease and render favorable," 1580s, a back-formation from propitiation and in part from propitiate (adj.), from Latin propitiatus, past participle of propitiare "appease, propitiate." Related: Propitiated; propitiating; propitiatingly; propitiable (1550s).
"conciliatory, intended to placate or appease," 1630s, from Latin placatorius "pertaining to appeasing," from placat-, past-participle stem of placare "to calm, appease, quiet, soothe, assuage," causative of placere "to please" (see please).
"act of making satisfaction or reparation for an offense, atonement, reparation," early 15c., expiacioun, from Latin expiationem (nominative expiatio) "satisfaction, atonement," noun of action from past-participle stem of expiare "make amends for, atone for; purge by sacrifice, make good," from ex- "completely" (see ex-) + piare "propitiate, appease," from pius "faithful, loyal, devout" (see pious).
The sacrifice of expiation is that which tendeth to appease the wrath of God. [Thomas Norton, translation of Calvin's "Institutes of Christian Religion," 1561]