to break a promise or agreement; to decide not to do something you said you would do.
Examples
He promised to help me move, but then he went back on his word at the last minute.
A: Did Sarah agree to join our project?
B: She did, but she went back on her promise and said she's too busy now.
Common mistake
Not: Don't go back your promise.
Say: Don't go back on your promise.
Needs 'on' — 'go back ON a promise / your word / the deal'.
More on “go back on”Another example · Tell it apart · Goes with · Tip
Another example
In my opinion, it's important not to go back on your promises, especially when working in a team.
Tell it apart
He went back on his word.
He went back to his old job.
Goes with
- go back on + commitment

