Makes someone happy or satisfied; gives joy or contentment to another person.
From Old French 'plaisir' (from Latin 'placere' meaning 'to be agreeable'), entering English in the 1200s. The verb form evolved to mean specifically the act of causing pleasure or happiness.
The Latin root 'placere' is where we also get 'placid' (calm/agreeable) and 'implacable' (impossible to satisfy)—so pleasing someone is literally about placing them in an agreeable state of mind.
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