'theft-resistant' originates from Modern English, specifically formed as a compound of 'theft' and 'resistant', where 'theft' meant 'the act of stealing' and 'resistant' derived from Latin 'resistere' meaning 'to stand back, oppose'.

'theft' comes from Old English 'þēft' (theft) ultimately from Proto-Germanic '*theubą' meaning 'seizure/stealing'; 'resistant' comes from Latin 'resistere' -> Old French 'resistant' and entered English as 'resistant'; these elements were combined in Modern English to form the compound 'theft-resistant'.

Initially, the components meant 'the act of stealing' (theft) and 'to resist or oppose' (resistere); over time they combined into the compound meaning 'designed to resist theft' in modern usage.