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to deprecate oneself and praise the listener; to abase oneself
彼は偉くなってもへりくだる姿勢がある。
Even though he became important, he has a humble attitude.
あまりへりくだりすぎるのもよくない。
Being too humble isn't good either.
目上の人にはへりくだって話すべきだ。
You should speak humbly to your superiors.