go back on

动词 go back on:

1. fail to fulfill a promise or obligation
   同义词：renege, renege on, renegue on

1. In advanced years a man's mind might go back on him at some unpredictable moment.
   上了年纪的人，脑子有时候会一下子不听使唤。
2. Don't go back on your word.
   可别说了不算数啊！
3. You should never go back on your promise to a child.
   你给孩子许了愿就千万不要食言。
4. His father told him not to go back on his promise.
   他的父亲对他说，不要违背自己的诺言。