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

The surgery has long been based on the idea that knee pain, especially on the inner side, is caused by a meniscus tear that can be fixed surgically.

From Science Daily • May 6, 2026

A major study with a 10-year follow-up has found that trimming a damaged meniscus does not improve symptoms or knee function when compared to a placebo procedure.

From Science Daily • May 6, 2026

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

From BBC • Feb. 15, 2026

Nine days ago, she suffered a torn ACL, a bone bruise and meniscus damage.

From Los Angeles Times • Feb. 8, 2026

The long semi-circular wall of precipice which, sweeping inwards at the bottom of the bay, leaves to the inhabitants between its base and the beach their fertile meniscus of land, here abuts upon the coast.

From The Cruise of the Betsey or, A Summer Ramble Among the Fossiliferous Deposits of the Hebrides. With Rambles of a Geologist or, Ten Thousand Miles Over the Fossiliferous Deposits of Scotland by Symonds, W. S. (William Samuel)

Related Words

• arc
• arch
• contour
• loop
• trajectory