break one's word
Violate or fail to observe a promise or contract one has made. For example, You can trust him implicitly; I've never known him to break his word. [c. a.d. 1000]
Words nearby break one's word
break one's ass,
break one's back,
break one's balls,
break one's fall,
break one's neck,
break one's word,
break out,
break out of,
break point,
break ranks,
break someone