- noun the characteristic of not allowing light or other rays to pass through
- noun the state of not allowing light to pass through
- In painting, the ability of a paint to cover or hide the original background.
- For a given body, material, or medium, a measure of the inability to transmit radiant energy, especially light, or sound. In the case of light, it may be quantified as the ratio of light flux incident upon a material, to the light flux transmitted by said material. It is the reciprocal of transmittance.
- noun the degree to which a material such as photographic film is able to stop light
- noun the fact of not allowing light to pass through
- noun an area in the eye which is not clear
- noun the quality of not allowing light through