From Longman Dictionary of Contemporary Englishfatalfa‧tal /ˈfeɪtl/ ●●○ adjective 1 DIEresulting in someone’s death potentially fatal diseasesfatal accident/illness/injury etc a fatal climbing accident If it is not treated correctly, the condition can prove fatal (=be fatal).2 HARM/BE BAD FORhaving a very bad effect, especially making someone fail or stop what they are doingfatal to Disunity finally proved fatal to the rebels’ cause. There was one fatal flaw (=serious weakness) in his argument. His presidential hopes suffered a fatal blow in New Hampshire.fatal mistake/error Telling your employees they’re unimportant is a fatal error.
Examples from the Corpus
fatal• The delay may be disappointing but is not fatal.• Meyer's car was involved in a fatal accident on the freeway.• Otherwise, he fears a fatal collision is on the horizon.• Recently I have experienced near fatal fevers.• a fatal heart attack• The gas can be fatal if inhaled in large amounts.• He suffered a fatal injury to the neck.• She will host the surprise get-together tomorrow as a thank you to the victims of a fatal muscle wasting disease.• Some were present in potentially fatal quantities.• Individual immortality would threaten the species as a whole - almost certainly with fatal results.• A sudden shock could be fatal to anyone with a weak heart.• Its fatal venom had no effect on him.prove fatal• Today an estimated 150,000 people are stung each year but less than 1 percent of these attacks prove fatal.• At worst you would get a severe electric shock, which could prove fatal.• In the case of the white-tailed hawk and other forms of wildlife, this destruction of suitable habitat may prove fatal.• One of them, 26 year old Anthony Clarke, gave him an injection of heroin which proved fatal.• That manoeuvre might lead to a diamond ruff for West at trick two, but even that is unlikely to prove fatal.• German measles can prove fatal to an unborn baby.• He said the fumes could have proved fatal to some one on their own or an older person.• The combination of recession, falling property values, rent and rate increases have proved fatal to the nation's business community.• The loss could prove fatal to their championship hopes.• An instantaneously absorbed dose of five grays would prove fatal within the space of two weeks.fatal mistake/error• But then we asked him a bit more about it and he made his fatal mistake.• But then, during the monsoon of 1661, she made her fatal mistake.• It was an expensive, almost financially fatal mistake.• This determination then leads him into his fatal error.• This may be a fatal mistake.• Which uncle had told him that was a fatal mistake?• It had made the fatal error of overkill.• I almost made a fatal mistake when she asked me to transfer the call to the Oval Office.Origin fatal (1300-1400) French Latin fatalis, from fatum; → FATE 