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to triumph; to be elated with success
彼は勝利に勝ち誇った。
He crowed over his victory.
妹は兄に勝ち誇って見せた。
My younger sister gloated to her older brother after winning.
討論に勝った彼は相手に勝ち誇るように話した。
Having won the debate, he spoke to his opponent as if to crow over his victory.