'convincer' originates from English, specifically formed from the verb 'convince' plus the agentive suffix '-er'. 'Convince' ultimately comes from Latin 'convincere', where 'con-' meant 'together' and 'vincere' meant 'to conquer or overcome'.

'convincer' developed after the verb 'convince' changed from Latin 'convincere' to Old French 'convaincre' and then to Middle English 'convincen'/'convince'; English then formed the agent noun by adding '-er' to create 'convincer'.

Initially, the Latin root meant 'to conquer or overcome'; over time this shifted to 'to prove or to persuade' in English, leading to the current sense of 'one who persuades or provides convincing evidence'.