guard dog

American  

Or guarddog

noun

1. a large, aggressive dog, as a German shepherd or Doberman pinscher, trained to guard persons or property and often to attack or restrain on command.

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Etymology

Origin of guard dog

First recorded in 1790–1800

Example Sentences

Anatol Ward, a Tokyo resident in his 50s, said the robot reminded him of a guard dog.

From Barron's • Jan. 30, 2026

Why buy a guard dog when the neighbor owns a wolf?

From MarketWatch • Jan. 10, 2026

The breed “is not the best choice for a guard dog since they are extremely friendly, even with strangers,” according to the United Kennel Club.

From Los Angeles Times • Jul. 22, 2025

To find out, the researchers asked Montana farmers who were regularly visited by grizzly bears to host a guard dog.

From Science Magazine • Apr. 11, 2024

“You know what a good guard dog goes for these days? I’ll tell you. There’s a German shepherd on the internet on sale for fifty-five thousand dollars. For one dog! Fifty-five K!”

From "Dog Squad" by Chris Grabenstein

Related Words

• attack dog