'anti-matrimonial' originates from a combination of the Greek prefix 'anti-' (from Ancient Greek 'ἀντί', meaning 'against') and the adjective 'matrimonial', which ultimately comes from Latin 'matrimonium' meaning 'marriage'.

'matrimonial' developed from Latin 'matrimonium' → Late Latin 'matrimonialis' and entered English as 'matrimonial'; the Greek prefix 'anti-' was later attached in modern English to form 'anti-matrimonial'.

Initially it literally meant 'against marriage'; over time the term has retained that core meaning but is used mainly in formal, ideological, or descriptive contexts to indicate opposition to marriage.