go back of 1. = go back on 2. = go behind/go back on 1. 背叛；出卖 Never go back on your friends. 永远不要出卖你的朋友。 2. 违背(诺言等) Promise you won't go back on our luncheon engagement. 我们已约好了一起吃午饭，答应我你不失约。 3. 使失望 In advanced years a man's mind might go back on him. 人上了年纪，脑子可能就不管用了。