Why was "tantrum" trending last week?
1580s, from French placation (16c.), from Latin placationem (nominative placatio) "an appeasing, pacifying, quieting," noun of action from past participle stem of placare (see placate).
1670s, a back-formation from placation or else from Latin placatus "soothed, quiet, gentle, calm, peaceful," past participle of placare "to calm, appease, quiet, soothe, assuage," related to placere "to please" (see please). Related: Placated; placating; placatingly.