'anti-matrimony' is formed from the prefix 'anti-' (from Greek 'anti', meaning 'against') combined with 'matrimony' (from Latin 'matrimonium').

'matrimony' originates from Latin 'matrimonium', where 'matri-' comes from 'mater' meaning 'mother' and the suffix '-monium' denoted a state or condition; it passed into Old French and Middle English (e.g. 'matrimonie') and eventually became the modern English 'matrimony'. The compound 'anti-matrimony' is a modern English formation using the productive prefix 'anti-'.

Initially, 'matrimony' related to the state of motherhood or the condition connected with being a mother and marriage; over time it came to mean 'marriage' generally. The compound 'anti-matrimony' has come to mean 'opposition to marriage' in contemporary usage.