meniscus

American  

[mi-nis-kuhs] / mɪˈnɪs kəs /

noun

plural

menisci, meniscuses

1. a crescent or a crescent-shaped body.

2. the convex or concave upper surface of a column of liquid, the curvature of which is caused by surface tension.

3. Optics. a lens with a crescent-shaped section; a concavo-convex or convexo-concave lens.

4. Anatomy. a disk of cartilage between the articulating ends of the bones in a joint.

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meniscus British  

/ mɪˈnɪskəs /

noun

1. the curved upper surface of a liquid standing in a tube, produced by the surface tension

2. a crescent or half-moon-shaped body or design

3. a crescent-shaped fibrous cartilage between the bones at certain joints, esp at the knee

4. a crescent-shaped lens; a concavo-convex or convexo-concave lens

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meniscus Scientific  

/ mə-nĭs′kəs /

plural

menisci

1. A lens that is concave on one side and convex on the other.

2. The curved upper surface of a column of liquid in a container. The surface is concave if the molecules of the liquid are attracted to the container walls and convex if they are not.

3. See also surface tension

4. A piece of cartilage shaped like a crescent and located at the junction of two bones in a joint. The meniscus acts to absorb shock.

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Other Word Forms

• meniscoid adjective

Etymology

Origin of meniscus

1685–95; < New Latin < Greek mēnískos crescent, diminutive of mḗnē moon

Explanation

The next time you pour some fluid into a tube, look at it from the side. You will see the liquid has a slight curve, either up or down. This curved surface, created by air pressure, is called a meniscus. The Greeks had a word for the lunar crescent, mēniskos, which itself came from the word for the moon, mḗnē. In the late 17th Century, the word meniscus was given to similarly-curved lenses. Then in 1812, the curved surfaces of liquid were referred to by this word as well. Later, the name was also applied to a crescent-shaped cartilage at the knee, between the tibia and the femur. These small, semi-lunar bits are important for reducing friction during leg movement.

Example Sentences

"But let's see how they respond, with no cartilage and no meniscus..."

From BBC • Feb. 15, 2026

She says along with the ACL tear she also has bruising and meniscus damage.

From BBC • Feb. 3, 2026

After the season, he underwent an operation to repair a damaged meniscus in his left knee.

From Barron's • Jan. 1, 2026

When she tore the same ACL and her medial meniscus last November, it took her a full year to recover, and then it took time to find her footing early this season.

From Los Angeles Times • Mar. 28, 2025

A correction must be introduced for the error caused by the meniscus of the mercury.

From The Methods of Glass Blowing and of Working Silica in the Oxy-Gas Flame For the use of chemical and physical students by Shenstone, W. A.

Related Words

• arc
• arch
• contour
• loop
• trajectory