To renege on a promise is to break your word and refuse to do what you said you would do. This can be a very harmful thing to do, because it ruins trust.
He reneged on his promise to help me with my project, and now I'm stuck doing it all by myself.
I was really looking forward to going to the party with you, but you reneged on your promise and said you weren't going.
noun
the mistake of not following suit when able to do so
Synonyms:
verb
fail to fulfill a promise or obligation
Synonyms:
1
The promise was promptly reneged upon him.
2
They are pressuring him to renege on his pledge not to raise tax rates.
3
It caused Sieloff to renege on his verbal commitment to play.
4
Mayor Paul Soglin says Madison will renege on its promise.
5
The Knave may renege if the Five is played.
6
The treaty was later reneged upon by him.
7
They reneged on contractual obligations made to employees.
8
British gas is about to renege on contract with Endesa.
9
It is up to the opposing players to spot the renege and call it.
10
The Nawab agreed, and did not renege over the deal.