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

It acts as a kind of guardian, Govan mused, like the lions that traditionally sit sentry beside libraries and museums.

From Los Angeles Times • Sep. 24, 2025

Two City of London Police officers have visited the sentry box and taken pictures.

From BBC • Aug. 11, 2024

The bank of elevators stand sentry in front of us.

From "It’s Kind of a Funny Story" by Ned Vizzini

Related Words

• sentinel