vigilant
Americanadjective
-
keenly watchful to detect danger; wary.
a vigilant sentry.
- Antonyms:
- careless
-
ever awake and alert; sleeplessly watchful.
- Synonyms:
- sleepless, wide-awake
adjective
Usage
What does vigilant mean? To be vigilant is to be watchful or alert for danger or some other kind of trouble. Vigilant can describe a person or an action. It is often used when talking about keeping something out or in—whether that means keeping mistakes out of your work, robbers out of your home, or the dog inside the house. Example: We must be vigilant if we want to protect our home from invaders.
Synonym Usage
See alert.
Other Word Forms
Etymology
Origin of vigilant
First recorded in 1470–80; from Latin vigilant- (stem of vigilāns ), present participle of vigilāre “to be watchful”; see vigil, -ant
Compare meaning
How does vigilant compare to similar and commonly confused words? Explore the most common comparisons:
Explanation
Use vigilant to describe someone who keeps awake and alert in order to avoid danger or problems. When taking the subway, be vigilant about your wallet — always know where it is, or someone might steal it from you. Vigilant descends from the Latin vigilare, "to be awake, watch," from vigil, "awake, alert." If you stay awake vigilantly all night, you're keeping watch or keeping a vigil. A vigilante (pronounced vij-uh-LAN-tee) is a person who acts outside the legal system to punish crime.
Vocabulary lists containing vigilant
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The Giver
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
He understands how to keep viewers vigilant, how to shock them and startle them as soon as they think they know where he’s headed.
From Salon ● Oct. 9, 2026
“The National Security Division and U.S. Attorney’s Offices, along with the FBI and other law enforcement partners, will remain vigilant against threats like this on our soil.”
From Los Angeles Times ● Oct. 5, 2026
In the meantime, if everyone remains vigilant and ready, we should make it safely to January.
From Slate ● Oct. 5, 2026
However, there is little doubt of the need to remain vigilant to guard against unexpectedly strong inflation.
From The Wall Street Journal ● Oct. 2, 2026
A vigilant and aggressive Food and Drug Administration, with a greatly increased force of inspectors, is another urgent need.
From "Silent Spring" by Rachel Carson
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Get a wordDefinitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.