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to show off; to flaunt
新しい車を見せびらかすように運転していた。
He was driving as if showing off his new car.
彼は新しい車を近所に見せびらかした。
He showed off his new car to the neighbors.
彼女は高級バッグを周りに見せびらかしている。
She is flaunting her luxury bag in front of everyone.