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

Watkins is coming back from an ACL injury that sidelined her for all of last season. — Doug Feinberg, Chicago Tribune, 29 Oct. 2026

Kyrie Irving is back after missing last year due to an ACL tear. — Outkick, FOXNews.com, 28 Oct. 2026

Watkins, who won the AP Player of the Year as a sophomore after tearing her ACL in the NCAA Tournament, is raring to go after sitting out last year while recovering from the injury. — ABC News, 28 Oct. 2026

He was projected as a preseason All-American and All-Big 12 performer in 2025, and then came the season-ending ACL tear in the fourth game. — Chris Hays, The Orlando Sentinel, 27 Oct. 2026

Word History

First Known Use

1981, in the meaning defined above

Medical Definition

ACL

noun

ˌā-(ˌ)sē-ˈel 

: anterior cruciate ligament