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.
Hours after the blaze broke out around noon on Thursday, Chinese leader Xi Jinping called for an investigation into the incident, urging officials to “draw profound lessons” and “always remain vigilant regarding production safety.”
From The Wall Street Journal • Jul. 10, 2026
In New York, the most populous US city, Mayor Zohran Mamdani urged residents to "stay cool, stay vigilant and check in on your neighbors."
From Barron's • Jul. 3, 2026
As the second-placed candidate he is entitled to a seat in the Senate, where he said he would exercise "a democratic, vigilant and constructive opposition".
From BBC • Jun. 24, 2026
But she also cautions investors “to be more vigilant in case there are any signs of oversupply across the AI supply chain.”
From MarketWatch • Jun. 24, 2026
He feels strangely vigilant, as if, were he to pay close enough attention, some sign of his father might manifest itself, putting a stop to the events of the day.
From "The Namesake" by Jhumpa Lahiri
Definitions 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.
