'exposer' originates from English, formed by adding the agentive suffix '-er' to the verb 'expose' (i.e., 'expose' + '-er' = 'exposer').

'expose' entered English from Old French Middle French 'exposer' (to set forth, exhibit), which itself came from Latin 'exponere' (ex- 'out' + ponere 'to put'). The modern English agent noun 'exposer' was formed later by English morphology.

Initially the root meant 'to put out' or 'to place outside'; over time it evolved to mean 'to make visible or reveal,' and the agent form 'exposer' came to mean 'one who reveals' or 'one that causes exposure.'