食言

食言 [shí yán]

1. ■ go back on one's word; break one's promise:

如果他答应帮忙， 他就不会食言。 If he promised to help, he will not go back on his promise.

他答应把书留给我之后， 却食言而把它卖给了别人。 After promising to keep the book for me, he broke his word and sold it to someone else.