Definition of on guard in US English:

on guard

phrase

  • 1On duty to protect or defend something.

    • ‘Some of the men had slipped away from the forward trenches, presumably those who were not actually meant to be on guard or patrol duty.’
    • ‘It is midnight and around me, except for the soldiers out on operations or on guard, 5,000 fighting men and their support staff are sleeping.’
    • ‘There would be no one on guard to protect the town from the Bandits.’
    • ‘Things soured after a six-year-old girl hurt herself when the dog on guard chased her in a bid to protect its family.’
    • ‘Another example shows Macdonald on guard outside the fort that protects Canadian industry.’
    1. 1.1 Prepared for any contingency; vigilant.
      ‘we must be on guard against such temptation’
      • ‘Growing up in the UK, it took me twenty-two long years to feel secure enough to adopt the feminist label, and even then I was always on my guard, prepared for the usual assumption that I was a bit odd.’
      • ‘It teaches you to keep on your guard and keep alert.’
      • ‘We have to be on our guard continuously against new and emerging infectious diseases.’
      • ‘If they come back we will be ready, we are on our guard.’
      • ‘Instead it had become a whispered warning and reminder to be constantly on our guard.’
      • ‘Constantly on his guard, he saves his passion for literature.’
      • ‘He immediately refers back to the episode he had witnessed, using it as his main example of the need to remain constantly on one's guard against princely duplicity.’
      • ‘As Christians we must constantly be on our guard not to be conformed to the world but, rather, to be transformed in our every thought.’
      • ‘I find myself constantly on my guard while shopping for fear of muggers, on foot or cycle.’
      • ‘It has alerted us to be continually on our guard hence security at airports and elsewhere.’
      vigilant, alert, on the alert, wary, watchful, cautious, careful, heedful, chary, circumspect, on the lookout, on the qui vive, on one's toes, prepared, ready, wideawake, attentive, observant, keeping one's eyes peeled
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