'theft-deterrent' originates from Modern English, specifically a compound of the words 'theft' and 'deterrent'. 'theft' originates from Old English, specifically the word 'þēof'/'þēof(t)', where the root meant 'thief' or 'stealing'; 'deterrent' originates from Latin, specifically the verb 'deterrēre', where the prefix 'de-' meant 'away' and 'terrēre' meant 'to frighten'.

'theft' was used in Old English and passed through Middle English with little change into modern English; 'deterrent' comes from Latin 'deterrēre' and entered English via Medieval/Modern usage as an agent/participle form (later noun/adjective). The compound 'theft-deterrent' is a modern English compound, becoming common in 20th-century security and retail contexts.

Initially, the components meant 'the act of stealing' (theft) and 'to frighten away' (deterrent); over time the compound came to mean 'something that discourages or prevents stealing' in contemporary usage.