Question

go back on one's word нарушить свое слово, обещание First he said he would help me, but then he <... his ...>.

Accepted Answer

break a promise First he said he would help me, but then he <went back on his word>.

idiom	go back on one's word
synonyms	break a promise
translation	нарушить свое слово, обещание
full_example	First he said he would help me, but then he <went back on his word>.
partial_example	First he said he would help me, but then he <... his ...>.

Back One's Word Break Promise нарушить свое слово