kneecap

American  

[nee-kap] / ˈniˌkæp /

noun

1. the patella.

2. a protective covering, usually knitted, for the knee.

---

verb (used with object)

kneecapped, kneecapping

1. to cripple (a person) by shooting in the knee.

   Terrorists were kneecapping prospective jurors.

kneecap British  

/ ˈniːˌkæp /

noun

1. anatomy a nontechnical name for patella

2. another word for poleyn

---

verb

1. (esp of certain terrorist groups) to shoot (a person) in the kneecap, esp as an act of retaliation

kneecap Scientific  

/ nē′kăp′ /

1. See patella

---

Other Word Forms

• kneecapper
  noun

Etymology

Origin of kneecap

First recorded in 1650–60; knee + cap ¹

Explanation

Your kneecap is the bony plate that covers the joint in the middle of your leg, between your thigh and shin. Whales don't have kneecaps, but it might surprise you to know that mice and birds do. The kneecap is just what it sounds like, a protective cap for your vulnerable knee. While the official anatomical term is patella, it's far more common to call this body part a kneecap. When babies are small, their kneecaps are made of soft cartilage, but by the time they're about three they harden into strong bone. If you're a fan of Mafia movies, you might also recognize the verb kneecap, "to shoot someone in the knee."

Example Sentences

Few if any government spokespeople have done more to kneecap their own agency in court than McLaughlin.

From Slate • Feb. 18, 2026

Hill suffered torn ligaments and a dislocated kneecap in a game against the New York Jets last year, ending his season.

From Barron's • Feb. 17, 2026

But traditional builders and single-family rental landlords are still grappling with how new restrictions, which need to be codified by Congress, could kneecap their businesses.

From The Wall Street Journal • Feb. 3, 2026

“I found out he broke his kneecap and I didn’t know what was going to happen,” Ansari continued, Reeves himself standing onstage just a few feet away.

From Los Angeles Times • Sep. 10, 2025

I feel a twinge just above my kneecap, but it only lasts a second.

From "The Sea in Winter" by Christine Day