Meniscus

n. pl. L. Menisci (-sī), E. Meniscuses (#).

1. A crescent.
2. (Opt.) A lens convex on one side and concave on the other.
3. (Anat.) An interarticular synovial cartilage or membrane; esp., one of the intervertebral synovial disks in some parts of the vertebral column of birds.
Converging meniscus, Diverging meniscus .
See Lens.