take leave of

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Also, take one's leave of. Depart from, say good-bye to. For example, Sorry but I have to take leave of you now, or After the movie we'll take our leave of you. [ Mid-1200s ]
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take leave of one's senses. Behave irrationally, act crazy, as in Give them the keys to the house? Have you taken leave of your senses? [ Late 1800s ]