'anti-clericalist' originates from a combination of Greek 'anti-' meaning 'against' and the adjective 'clerical' (from 'cleric'), with the agentive suffix '-ist' (from Greek/Latin/French) forming a noun meaning 'one who is against clericalism'.

'anti-clericalist' developed in English from French formations such as 'anticléricaliste' and the noun 'anticléricalisme' (19th century), itself built from 'anticlérical' ('anti-' + 'clérical'), which traces 'clérical' to Latin 'clericus' and Greek 'klerikos'.

Initially used to describe political movements and people opposed to clerical influence (especially in 19th-century Europe); it has largely retained that sense, though it can now also apply more broadly to opposition to institutional religious influence in public affairs.