booとは何ですか?A sound uttered to show contempt, scorn, or disapproval.Informal Any sound or word: You never said boo to me about overtime. Used to express contempt, scorn, or disapproval or to frighten or surprise another.To utter a boo.To express contempt, scorn, or disapproval of by booing: booed the singer off the stage. Slang Marijuana.