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
Derived 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
100 Words Every Middle Schooler Should Know
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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.
In the L.A. area, Flock has gone head to head with competitor Vigilant Solutions, which has for years supplied the majority of the LAPD’s plate readers.
From Los Angeles Times • Mar. 1, 2026
The operation is part of Project Vigilant, a national police initiative to combat sexual violence.
From BBC • Aug. 25, 2023
James Carroll, vice president of federal programs with the California company Vigilant Drone Defense, said his firm aims to make those distinctions quickly.
From Washington Times • May 20, 2023
Twice Vigilant: I really like the idea of training store employees about this increasingly common scam.
From Washington Post • Feb. 28, 2023
But, Captain," answered Vigilant, "we have searched for the guard, and can't find him.
From Old Farm Fairies: A Summer Campaign In Brownieland Against King Cobweaver's Pixies by McCook, Henry Christopher
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.
