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

She’s such a good family dog and incredible guard dog.

From Los Angeles Times • Jun. 6, 2025

But now, Young and a colleague have published new research that suggests farmers could turn to an ancient human ally, the guard dog, to scare grizzlies away cheaply and effectively.

From Science Magazine • Apr. 11, 2024

Harlan Betchel hadn’t opened up yet; his guard dog, Brutus, sat in the window, staring alertly across the street at O. J. and Snuffy Ledoux.

From "The Milagro Beanfield War" by John Nichols

Related Words

• attack dog