The word 'trigger' entered English in the early 17th century from Dutch 'trekker', meaning 'that which pulls', from the verb 'trekken' (to pull). This Dutch term itself has Germanic origins, related to Old English 'treccan' (to pull, drag) and Middle Low German 'trecken'. The original, literal sense referred to the lever pulled to release a mechanism, specifically on a firearm. Over time, the meaning broadened metaphorically to describe any small event that initiates a larger, often rapid, sequence of actions, perfectly capturing the causal logic of its mechanical origin.

The word is a simplex form. It is a loanword from Dutch, derived from the earlier Dutch word 'trekker', meaning 'pull' or 'draw'. Its functional role is as a complete lexical unit.