ACL

noun

ˌā-(ˌ)sē-ˈel 

plural ACLs

: a cruciate ligament of each knee that attaches the front of the tibia with the back of the femur and functions especially to prevent hyperextension of the knee and is subject to injury especially by tearing

The athlete tore their ACL during a practice game.

called also anterior cruciate ligament

Examples of ACL in a Sentence

Recent Examples on the Web

Houston quarterback Graham Mertz tore his ACL in the Texans’ opener and is out for the season. — Jason Lloyd, New York Times, 21 Aug. 2026

He was promoted to the Raw brand after WrestleMania 40 but a torn ACL injury kept him on the shelf for a year. — Ryan Gaydos Outkick, FOXNews.com, 20 Aug. 2026

Sure, those reasons included injuries, particularly Patrick Mahomes’ torn ACL and LCL. — Kansas City Star, 19 Aug. 2026

The Virginia native has torn her ACL twice, once in 2019 and again in 2023. — Lawrence Dow, Fort Worth Star-Telegram, 19 Aug. 2026

Word History

First Known Use

1981, in the meaning defined above

Medical Definition

ACL

noun

ˌā-(ˌ)sē-ˈel 

: anterior cruciate ligament