dishonour2 British English ; dishonor American English [transitive]
to make your family, country, profession etc lose the respect of other people:
He dishonored the uniform and did not deserve to be a marine.
if a bank dishonours a cheque, it refuses to pay out money for it [≠ honour]
to refuse to keep an agreement or promise [≠ honour]:
Union leaders accused management of dishonouring existing pay agreements.