Definition

1. Noun (Physics):

   • The curved upper surface of a liquid in a container, caused by surface tension. This curvature can be either concave (curving upward, as with water in a glass tube) or convex (curving downward, as with mercury).

2. Noun (Optics):

   • A lens that is concave on one side and convex on the other. This shape converges or diverges light rays and is commonly used in optical instruments like cameras, eyeglasses, and telescopes.

3. Noun (Anatomy):

   • A crescent-shaped piece of fibrocartilage situated between the articulating surfaces of some joints, most notably the knee. It acts as a shock absorber and stabilizer.

Usage Examples

• Physics:

  • When measuring water in a graduated cylinder, read the measurement at the bottom of the meniscus for accuracy.
  • The mercury in the thermometer formed a convex meniscus.

• Optics:

  • The telescope's objective lens is a meniscus designed to reduce optical aberrations.
  • Some eyeglass lenses use a meniscus design to be both thin and effective.

• Anatomy:

  • The athlete tore his medial meniscus during the game, requiring surgery.
  • The meniscus in the knee joint helps distribute weight and reduce friction.

Advanced Usage

• "To read the meniscus": A standard laboratory instruction meaning to observe the curved surface of a liquid at eye level to take an accurate volume measurement.
  • Always read the meniscus at eye level to avoid parallax error.

Variants and Related Words

• Meniscal (adj): Pertaining to or of the nature of a meniscus.

  • The patient underwent meniscal repair surgery.

• Meniscectomy (n): The surgical removal of all or part of a torn meniscus in the knee.

• Meniscoid (adj): Resembling a meniscus in shape.

Synonyms

• Physics: Curvature, concave surface, convex surface.
• Optics: Concavo-convex lens, lens.
• Anatomy: Cartilage, fibrocartilage disc.

Related Phrases

• Meniscus sign: A radiological term for a specific appearance of a fluid level on an X-ray.
• Torn meniscus: A common injury referring to damage of the knee cartilage.

Noun

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