A small slit in a garment where a button passes through, or to stop someone and force them to listen to you.
From 'button' + 'hole'; the noun emerged in the 1600s for the slit in fabric, and the verb (meaning to accost someone) developed by the 1800s from the idea of grabbing someone's buttonhole.
Victorian gentlemen developed the verb 'buttonhole' because fashionable coat buttons were often ornate—physically grabbing someone's buttonhole was one way to keep their attention in conversation!
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