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sentry

American  
[sen-tree] / ˈsɛn tri /

noun

sentries plural
  1. a soldier stationed at a place to stand guard and prevent the passage of unauthorized persons, watch for fires, etc., especially a sentinel stationed at a pass, gate, opening in a defense work, or the like.

  2. a member of a guard or watch.


sentry British  
/ ˈsɛntrɪ /

noun

  1. a soldier who guards or prevents unauthorized access to a place, keeps watch for danger, etc

  2. the watch kept by a sentry

"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

Other Word Forms

Noun Inflected Forms

Etymology

Origin of sentry

1605–15; short for sentrinel, variant of sentinel

Explanation

A sentry is someone who stands guard or watches against some intrusion or unwelcome activity. Your dog stands sentry over your house, but he would be more effective if he barked at strangers instead of licking their hands. The noun sentry came from the French sentinelle, which has a similar meaning. It was in the 17th century that the word was first associated with someone on a watchtower as a military guard. You could only enter the dreaded ice fortress after sneaking past the sentry posted outside. Don't let his button eyes and carrot nose fool you — he's a sharp one!

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Vocabulary lists containing sentry

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.

As a stopgap, the VA brought on a private security firm in June to provide uniformed 24-hour “observe and report” sentry posts and roving patrols.

From Los Angeles Times • Jun. 26, 2026

An outpost for 30 soldiers with a couple of sentry points and barracks will burn through about 13 gallons of fuel a day.

From The Wall Street Journal • Dec. 25, 2025

Barcelona stretched out in every direction, a mosaic of old stone, glass and spire, Gaudí’s Sagrada Familia standing like an undone sentry among the rest.

From Salon • Dec. 6, 2025

It comes a day after painted swimming piranhas on to a City of London Police sentry box, which was first spotted on Sunday morning.

From BBC • Aug. 12, 2024

Michael stands at the door like a sentry, clipboard in hand, checking in all the new arrivals, faithfully keeping the count.

From "Linked" by Gordon Korman

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