'antisimoniac' originates from the prefix 'anti-' (from Greek anti-, meaning 'against') combined with 'simoniac' (relating to 'simony'), where 'anti-' meant 'against' and 'simoniac' referred to matters relating to 'simony' (the buying or selling of ecclesiastical offices).

'simony' itself derives from Late Latin 'simonia', ultimately referring to the name 'Simon' (from the New Testament figure Simon Magus). English formed 'simoniac' (relating to simony) and then compounds such as 'antisimoniac' (against simoniacs or simony) appeared in post-medieval/modern English usage; the adjective form 'antisimoniacal' has also been used.

Initially it meant 'against simony (the sale of church offices)', and that core meaning has been largely retained, though the term is now rare and mainly historical or literary.