打招呼 1.(用语言或动作表示问候) greet sb.; say hello; tip one's hat2.(事先提醒) give a previous notice; warn; remind; notify in advance; inform 事先打招呼了吗? have you warned beforehand?3.(事先通知、关照) notify; let sb. know 你什么时候去北京, 给我打个招呼。 when you go to beijing, please let me know