英汉词典

1. 失信于；辜负
    If you betray someone who loves or trusts you, your actions hurt and disappoint them.

    e.g. When I tell someone I will not betray his confidence I keep my word...
           如果我告诉某人我不会辜负他的信任，我就会恪守诺言。
    e.g. The President betrayed them when he went back on his promise not to raise taxes.
           总统背叛了他们，违背了不加税的诺言。