Lie of omission Share definition Flag A lie when you purposely dont tell someone something cause you know they won't like it. Any lie is still a lie. You committed a lie of omission by not telling me you cheated with your ex. Lie of omission by DoNotLie August 13, 2017 0 0 Get merch Get the Lie of omission mug. Buy Now — $32.95 See more merch