'pro-abortion-rights' originates from the Latin prefix 'pro-' meaning 'for' combined with the English noun 'abortion' (from Latin 'abortio') and the English noun 'rights' (from Old English 'riht'), where 'pro-' meant 'for', 'abortio' meant 'a miscarriage or premature birth', and 'riht' meant 'just' or 'straight'.

'pro-abortion-rights' formed in modern English by combining the prefix 'pro-' with the established nouns 'abortion' and 'rights'; 'abortion' itself derives from Latin 'abortio' (via Medieval and Renaissance Latin usage) and 'rights' derives from Old English 'riht' through Middle English 'right'; the full hyphenated political label emerged in the late 20th century in public and media discourse.

Initially, the component words referred separately to being 'for' something, the medical act 'abortion', and the concept of 'rights'; over time their combination evolved into a concise political label meaning 'in favor of the legal right to abortion'.