'straight-edged' is formed from the adjective 'straight' + the past-participial adjective-form of 'edge' ('edged'), in Modern English; 'straight' ultimately comes from Old English and Proto-Germanic roots meaning 'not bent', and 'edge' comes from Old English 'ecg' meaning 'border' or 'blade'.

'straight' originates from Old English 'streht/stræht' (from Proto-Germanic *straihtaz) meaning 'straight'; 'edge' originates from Old English 'ecg' (Proto-Germanic *agjo). The compound 'straight-edge' (noun) arose by joining the two words in Modern English; the adjectival form 'straight-edged' was formed by adding the past-participial -ed to 'edge' to mean 'having a straight edge'. The cultural sense ('straight edge' as a lifestyle) developed in the early 1980s within the hardcore punk scene.

Initially the phrase described a literal physical quality—'having a straight edge'—but in the 20th century it acquired an additional cultural meaning referring to the straight edge movement (abstaining from alcohol and drugs). Both senses remain in use.