on a promise

on a promise

On the understanding that something will be done as someone has promised. He agreed to overtake the project on top of his existing work on a promise of a pay raise. We decided to let it go without punishing John on a promise that he will not attend any of these parties ever again.
See also: on, promise
Farlex Dictionary of Idioms.

on a promise

(of a person) confidently assured of something, especially of having sexual intercourse with someone. informal
See also: on, promise
Farlex Partner Idioms Dictionary
See also:
  • promise (one) the moon
  • promise someone the moon
  • promise the moon
  • promise the moon/earth/world
  • win (something) by a hair
  • win (something) by a neck
  • win (something) by a nose
  • win (something) by a whisker
  • win by a neck
  • win by a nose