'pro-nuptial' is formed from the Latin prefix 'pro-' and the adjective 'nuptial', where 'pro-' meant 'for' and 'nuptial' derives from Latin 'nuptialis' (relating to marriage).

'nuptial' comes from Latin 'nuptialis' (from 'nuptia'/'nubere' meaning 'marriage'/'to marry') and entered English via Old French/Medieval Latin; the modern compound 'pro-nuptial' is a later formation in English combining 'pro-' + 'nuptial'.

Originally built from elements meaning 'for marriage', it has come to be used in modern English to mean 'favouring or promoting marriage' or 'relating to marriage'.