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vigilant

[vij-uh-luhnt]
adjective
  1. keenly watchful to detect danger; wary: a vigilant sentry.
  2. ever awake and alert; sleeplessly watchful.
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Origin of vigilant

1470–80; < Latin vigilant- (stem of vigilāns), present participle of vigilāre to be watchful. See vigil, -ant
Related formsvig·i·lant·ly, adverbvig·i·lant·ness, nounhy·per·vig·i·lant, adjectivehy·per·vig·i·lant·ly, adverbhy·per·vig·i·lant·ness, nounnon·vig·i·lant, adjectivenon·vig·i·lant·ly, adverbnon·vig·i·lant·ness, nounpre·vig·i·lant, adjectivepre·vig·i·lant·ly, adverbsu·per·vig·i·lant, adjectivesu·per·vig·i·lant·ly, adverbun·vig·i·lant, adjectiveun·vig·i·lant·ly, adverb
Can be confusedvigilant vigilante

Synonyms

2. wide-awake, sleepless.

Synonym study

2. See alert.

Antonyms

1. careless.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for hypervigilant

vigilant

adjective
  1. keenly alert to or heedful of trouble or danger, as while others are sleeping or unsuspicious
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Derived Formsvigilantly, adverbvigilantness, noun

Word Origin

C15: from Latin vigilāns keeping awake, from vigilāre to be watchful; see vigil
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for hypervigilant

vigilant

adj.

late 15c., from Latin vigilantia "wakefulness," from vigilia (see vigil). Related: Vigilantly.

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Online Etymology Dictionary, © 2010 Douglas Harper