gym rat

American

[jim rat] / ˈdʒɪm ˌræt /

noun

Slang.

an exercise and fitness enthusiast who spends a lot of time at the gym, working out frequently or for long periods of time.

Whether you're a gym rat or a total newbie, these sets are worth exploring.

Etymology

Origin of gym rat

First recorded in 1970–75

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.

But however you categorize this subculture, it may provide some clues to understanding how a gym rat could encounter militant new ideas.

From Slate • Jan. 22, 2026

On his dating profile, Harkins presented himself as a jet-setting, business-owning "gym rat", but in reality he was a prolific and predatory fraudster.

From BBC • Nov. 22, 2025

He is the gym rat who will be in the gym at 6 a.m. shooting with players until late at night.

From Seattle Times • May 2, 2024

A gym rat, Ralphie pumps iron to make up for the fact that he doesn’t feel very manly.

From New York Times • Nov. 9, 2023

He’s an über-jock and a gym rat, but he lives in such fear of illness that he never wants to get close enough to anyone to catch anything they might have or be carrying.

From "Liar, Liar" by Gary Paulsen

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023