'anti-theft' originates from Modern English, specifically formed from the prefix 'anti-' (from Greek 'anti' meaning 'against') combined with the noun 'theft' (from Old English 'þēofth' meaning 'stealing').

'anti-' entered English usage via Latin and Old French as a productive prefix meaning 'against'; 'theft' changed from Old English 'þēofth'/'þēof' to Middle English 'theft' and eventually to modern English 'theft', and the compound 'anti-theft' was formed in Modern English to describe measures against theft.

Initially, the components meant 'against' and 'stealing'; combined in Modern English they specifically mean 'designed to prevent theft' (the sense has become a stable compound meaning 'for preventing theft').