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]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. Related Words for break one’s word ignore, neglect, omit, forget, slight, fault, overlook, blink, discount, abort, slip, disregard, disappoint, miscarry, desert, funk, betray, renege, overpass