To express strong disagreement or protest about something, usually by reasoning earnestly with someone.
From Latin expostulare (to demand, protest), from ex- (out) + postulare (to demand). This is actually unrelated to 'expose'—it's a completely different root that happens to start with 'expo-'.
Expostulate is often confused with expose because they sound similar, but they come from totally different Latin roots! To expostulate is to argue or protest (like 'I expostulate against this decision'), while expose means to reveal or uncover.
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