- 1 causing or ending in death a fatal accident/blow/illness a potentially fatal form of cancer If she gets sick again, it could prove fatal. compare mortal
- 2 causing disaster or failure a fatal error/mistake Any delay would be fatal. There was a fatal flaw in the plan. It would be fatal to try and stop them now.
fatallyjump to other results
NAmE//ˈfeɪt̮l̩i//adverb fatally injured/wounded The plan was fatally flawed from the start.