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

While coach Paul Maurice was unable to confirm the severity of the injury in his postgame press conference, Florida fans are especially anxious, considering an ACL tear kept Barkov out for the entire season last year. — Austin Perry Outkick, FOXNews.com, 2 Oct. 2026

The record closed out the 13-song set, which ended in a staggering high note from Spiro and a standing ovation from a stunned ACL audience. — Larisha Paul, Rolling Stone, 2 Oct. 2026

The winning streak has put all eyes back on Kansas City, as quarterback Patrick Mahomes has showed no signs of slowing down after tearing his left ACL in November 2025, and running back Kenneth Walker has added a new dynamic to the offense. — Joseph Hernandez, Kansas City Star, 29 Sep. 2026

Harbaugh’s aggressive trade demonstrates urgency to keep improving a 2-1 Giants team that is teetering after losing Dart and edge rusher Brian Burns (torn right ACL) to season-ending knee injuries in a seven-day span. — Pat Leonard, New York Daily News, 28 Sep. 2026

Word History

First Known Use

1981, in the meaning defined above

Medical Definition

ACL

noun

ˌā-(ˌ)sē-ˈel 

: anterior cruciate ligament