'placater' originates from English, formed from the verb 'placate,' which ultimately comes from Latin 'placare,' where 'placare' meant 'to please' or 'to appease'.

'placate' entered English in the late 16th century from Latin (via past participle 'placatus' / verb 'placare'). The agent noun 'placater' was later formed in English by adding the suffix '-er' to 'placate', and 'placaters' is the plural.

Initially the Latin root meant 'to please' or 'to make calm'; over time English developed the sense 'to appease or pacify,' and 'placater' now means 'one who placates' (someone who soothes or appeases others).