'appointer' originates from English as an agent noun formed from the verb 'appoint' + the agentive suffix '-er'. The verb 'appoint' comes from Old French 'apointer' (or 'apointier'), ultimately built from Latin elements 'ad-' meaning 'to/toward' and 'punctum' meaning 'point'.

'appoint' entered Middle English from Old French 'apointer'/'apointier'; English then formed the agent noun 'appointer' (verb + '-er'), and the modern English plural form became 'appointers'.

Initially, related words conveyed the sense 'to bring to a point' or 'to arrange/settle'; over time 'appoint' developed the specific sense 'to designate or assign someone to an office or duty', so 'appointer' came to mean 'one who appoints'.