Definition of lethal in English:



  • 1Sufficient to cause death.

    ‘a lethal cocktail of drink and pills’
    • ‘In fact, oxidative stress may progress to such an extent that it becomes lethal.’
    • ‘Many dogs like the sweet smell and taste and, unfortunately, even very small amounts can be lethal to them.’
    • ‘In the United States, critically injured racehorses are humanely euthanized by lethal injection.’
    • ‘Without the respectability that lethal injection provides, capital punishment in the United States would probably cease.’
    • ‘Who's to say that a substance lethal to rats would necessarily have the same effect on humans?’
    • ‘Grey squirrels have out-competed reds for food and also carry squirrel-pox virus which is lethal to the native animals.’
    • ‘The offender appears to sleep peacefully before the lethal dose of poison is administered.’
    • ‘Every car is a potentially lethal weapon of mass destruction.’
    • ‘All four incidents involving the potentially lethal weapon happened within the space of an hour in Grimsby.’
    • ‘Antibiotics are medicines that are lethal to bacteria that cause infections.’
    • ‘They're exposed every day to potentially lethal doses of anthrax.’
    • ‘In sufficient quantities its spores can be lethal to humans.’
    • ‘Such a hostile chemical environment would likely prove lethal to all known microbes.’
    • ‘The gas acts like mustard gas, and can prove lethal to those with respiratory problems.’
    • ‘The first, a yeast, can be especially lethal to individuals with weakened immune systems.’
    • ‘Actually, the mutation has proved lethal in a protected environment as well.’
    • ‘A deadly bird flu, lethal to some animals, is spreading towards Britain.’
    • ‘The synthetically lethal combinations could not be analyzed because they did not grow under any conditions.’
    • ‘Although scorpion stings can be devastatingly painful, they are not usually lethal to humans.’
    • ‘The avian flu strain lethal to humans has so far killed 42 people in Vietnam since late 2003.’
    1. 1.1Very harmful or destructive.
      ‘the Krakatoa eruption was the most lethal on record’
      • ‘Too much time and money, little purpose, and boredom are a lethal combination.’
      • ‘In our schools, too, we should emphasize that it will be lethal to take the earth for granted.’
      • ‘Friday was a bizarre affair, fuelled by a lethal combination of beer, wine, Jack Daniels and vodka.’
      • ‘It's not just inactivity that makes excess TV-watching lethal to your waistline.’
      • ‘Add to that an unhealthy dose of shame at her previous level of comfort, and you had a lethal combination.’
      • ‘That's a lethal combination when you're required to spend two hours with someone in a car.’
      • ‘Added to that is booze, which can make a lethal combination when added to football, causing fights and car accidents.’
      • ‘Entire governments, never mind single ministers, have been toppled by that lethal combination.’
      • ‘The lethal combination of peak hour traffic and rain had resulted in chaos on the roads.’
      • ‘Are you prepared to consume that lethal dose of sodium and fat?’
      • ‘The cider and vodka combination is far too lethal for my poor liver so I ended up puking.’
      fatal, deadly, mortal, causing death, death-dealing, life-threatening, murderous, homicidal, killing, terminal, final, incurable
      poisonous, toxic, virulent, noxious, venomous
      dangerous, destructive, harmful, pernicious, malignant, disastrous, calamitous, ruinous
      deathly, nocuous, mephitic
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    2. 1.2(in a sporting context) very accurate or skilful.
      ‘a lethal drop-shot’
      • ‘Beautifully balanced and deceptively fast, he was a classic winger on the dribble, lethal on the turn inside the box.’
      • ‘He is a true winger in the Ryan Giggs mould, hugging the touchline and whipping in crosses and lethal shots in great quantity.’
      • ‘The diminutive striker displayed a lethal eye for goal for the Blues two seasons ago and was one of the top scorers in the Premiership.’
      • ‘Gooden is a tough cookie who can score, and Giricek is a lethal shooter who is underrated at being aggressive.’
      • ‘Despite scoring just nine goals in the league Manchester United possess potentially the most lethal striking quartet in the country.’
      • ‘Most other clubs can only drool at our rich vein of lethal finishers.’
      • ‘The Bills' lethal vertical passing game will be tough to stop the rest of the season.’
      • ‘He can catch the ball in traffic as well as anyone in the league, and he's lethal after the catch.’
      • ‘Sirotka doesn't blow hitters away with a big fastball, but he throws a lethal sinker and gets a lot of groundouts.’
      • ‘The striker was lethal with his finish, firing a beautiful curling shot that gave Williams no chance.’
      • ‘Seven minutes before the break, however, Argentina once more showed how lethal they are when Riquelme is given time on the ball.’
      • ‘Still only 19 years old, Ronaldo has gone from promising starlet to lethal player since the turn of the year.’
      • ‘His connection with quarterback Jake Delhomme is almost telepathic, and his speed is lethal.’
      • ‘Rivaldo is equipped with a lethal left foot that has gone through more than a few defences.’
      • ‘He has shown his lethal shooting touch but has yet to go on a tear, creating speculation he doesn't have much left.’
      • ‘With a lethal combination of range, strength and speed, Boston is a big play waiting to happen.’
      • ‘The Real Madrid and former Inter striker whose credit includes sporting one of the worst haircuts in living memory is lethal in front of goal.’
      • ‘Maloney is a diminutive treasure, a pint-sized magician and, from free kicks, consistently lethal.’
      • ‘In the ring he is lethal, arguably the quickest fighter in history, with sneaky power and a flair for the dramatic.’
      • ‘Rush was one of the most lethal forwards of the past 25 years.’
      well aimed, precise, on target, unerring, deadly, sure, true, on the mark, careful, meticulous, painstaking, precision
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Late 16th century (in the sense ‘causing spiritual death’): from Latin lethalis, from lethum, a variant (influenced by Greek lēthē forgetfulness), of letum death.