AR15

noun

ˈāˈär(ˈ)fif¦tēn

variants or AR15 rifle

plural -s

: a . 223 caliber gas-operated semiautomatic rifle that is essentially a civilian version of the M16

Word History

Etymology

from Armalite, the manufacturer

First Known Use

1963, in the meaning defined above

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now