your, his, etc. word of honour

(one's) word (of honor)

One's sincere promise or vow (about or to do something). I will be in that court to stand by your side during the trail—I give you my word of honor. After the president broke his word about lowering taxes for middle-class earners, I vowed never to vote for him again.
See also: word
Farlex Dictionary of Idioms.

your, his, etc. ˌword of ˈhonour

(British English) (American English your, his, etc. ˌword of ˈhonor) used to refer to somebody’s sincere promise: He gave me his word of honour that he’d never drink again.
See also: honour, of, word
Farlex Partner Idioms Dictionary
See also:
  • (one's) word (of honor)
  • word
  • word of honor
  • give (someone) (one's) word
  • give somebody your word
  • (one's) day in court
  • at (one's) doorstep
  • be oneself
  • be yourself
  • at (one's) expense