Definition of crucial in US English:



  • 1Decisive or critical, especially in the success or failure of something.

    ‘negotiations were at a crucial stage’
    • ‘The decision on where to film was crucial to the success of the dramas.’
    • ‘Bad management and bad cost control will be crucial in deciding success or failure.’
    • ‘We do appear to be at a crucial juncture, to say the least.’
    • ‘Coach Gary Moorby was particularly pleased with this crucial factor in the Cougar victory.’
    • ‘Certainly, Conroy's interventions were crucial to the outcome of the game.’
    • ‘The committee is asking for continued support as we are at a crucial stage in the campaign.’
    • ‘This could mean that wrong decisions are made at crucial moments - and these cannot be reversed.’
    • ‘We have reached a crucial stage and now tenants and residents will begin to see real improvements on their estate.’
    • ‘His error was made at a crucial stage in the match but he couldn't deny the funny side.’
    • ‘A crucial factor in the rise was the growing number of women who smoke.’
    • ‘Ambitious plans to complete a town centre pedestrianisation zone have reached a crucial stage.’
    • ‘I see the next 18 months as crucial to the long-term development of the game.’
    • ‘Ultimately, these incidents probably did not prove crucial to the outcome.’
    • ‘The chemistry so crucial to the success of any screen romance is absent.’
    • ‘A near doubling of the share values would be a crucial factor in any decision that is made.’
    • ‘His appointment comes at a crucial stage in this long-running drugs war.’
    • ‘There are no elements more important than others, but timing is crucial.’
    • ‘Williams now faces a crucial decision as to which direction he takes his career.’
    • ‘Watson believes conceding a goal so early on Tuesday was crucial to the outcome.’
    • ‘God knew all logic flew out the window that crucial moment.’
    pivotal, critical, key, climacteric, decisive, deciding, determining, settling, testing, trying, searching
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    1. 1.1 Of great importance.
      ‘this game is crucial to our survival’
      • ‘Once he understands that crucial difference, he should get off to a good start.’
      • ‘If you want to lose weight, it is crucial to maintain low insulin levels.’
      • ‘Strategies for effective communication and involvement are crucial at this stage.’
      • ‘All low-carb foods are not created equal, and it's crucial to understand the differences.’
      • ‘Insight, understanding and enjoyment are the keys to making newspapers crucial.’
      • ‘Everyone was aware that those games weren't crucial, and it was just the group stage.’
      • ‘Only 15 percent mentioned domestic policies as being most crucial to them.’
      • ‘It is crucial to keep your head covered when running outside in winter.’
      • ‘For, low as this may seem, the most crucial industries had been successfully moved.’
      • ‘Improved road links are crucial to developments in Pembroke Dock and the Angle peninsula.’
      • ‘Finding species that are unknown to science is crucial to their continued survival, he says.’
      • ‘Solidarity through donations is crucial to ensure the strike does not fail through lack of money.’
      • ‘Since variation was the essence of evolution, it was crucial to understand its nature.’
      • ‘All the time, it is crucial to remember that we are never alone.’
      • ‘Sesame is great for iron, a crucial mineral for maintaining vital energy levels.’
      • ‘He was singled out by the judge for stinging criticism, and accused of removing crucial evidence.’
      • ‘Monitoring blood lipids is crucial to ensure that the diet is having the desired effect.’
      • ‘I make no apologies for this because it is absolutely crucial to the future economic success of the nation.’
      • ‘Participation by trustees is crucial to their understanding of the issues before the board.’
      • ‘One crucial element of the luxury shopping experience is the service and setting.’
      very important, of the utmost importance, of great consequence, of the essence, critical, high-priority, pre-eminent, paramount, all-important, essential, vital, vitally important, indispensable, mandatory, urgent, pressing, compelling, necessary, needed, required, requisite
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Crucial is used in formal contexts to mean ‘decisive, critical’: the testimony of the only eyewitness was crucial to the case. Its broader use to mean ‘very important’ should be restricted to informal contexts: it is crucial to get good light for your photographs


Early 18th century (in the sense ‘cross-shaped’): from French, from Latin crux, cruc- ‘cross’. The sense ‘decisive’ is from Francis Bacon's Latin phrase instantia crucis ‘crucial instance’, which he explained as a metaphor from a crux or fingerpost marking a fork at a crossroad; Newton and Boyle took up the metaphor in experimentum crucis ‘crucial experiment’.