/oh pas"i tee/ , n. , pl. opacities .
1. the state or quality of being opaque.
2. something opaque.
3. the degree to which a substance is opaque; capacity for being opaque.
4. Photog. the proportion of the light that is absorbed by the emulsion on any given area of a film or plate.
5. obscurity of meaning.
6. mental dullness.
7. Med. an opaque spot or area in normally clear or transparent tissue, as a cataract of the eye.
[ 1550-60; opacitas shade. See OPAQUE, -ITY ]