go back on

US /ɡoʊ bæk ɑːn/
UK /ɡoʊ bæk ɑːn/
"go back on" picture
1.

食言, 违背

fail to keep a promise or agreement

:
He promised to help me, but he went back on his word.
他答应帮我,但他食言了
You can't just go back on our agreement now.
你不能现在就违背我们的协议。