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.
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(optics) a lens that is concave on one side and convex on the other
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2 |
n |
(physics) the curved upper surface of a nonturbulent liquid in a vertical tube
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3 |
n |
(anatomy) a disk of cartilage that serves as a cushion between the ends of bones that meet at a joint
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