A person who answers a question, responds to a query, or provides a response to something.
From answer plus the agent suffix -er (from Old English -ere), which creates a noun denoting someone who performs an action.
The word 'answerer' is surprisingly rare in modern English, even though we frequently talk about 'answerers' in contexts like trivia contests, tech support, or philosophy—maybe because we prefer saying 'the person who answered' instead!
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