sentry

American  

[sen-tree] / ˈsɛn tri /

noun

plural

sentries

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.

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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

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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!

Example Sentences

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

The sentry box is a short distance from landmarks such as the Old Bailey and St Paul's Cathedral.

From BBC • Aug. 11, 2024

And so Friday, families trickled in starting at 8:15 a.m. while private security guards stood sentry.

From Los Angeles Times • May 10, 2024

I leapt over the remains of a sentry fire, bumped into a gray- bearded soldier wearing a homespun shirt, and startled a man carrying two live hens by the feet.

From "Chains" by Laurie Halse Anderson

Related Words

• sentinel