(n) A regional or social variety of a language distinguished by pronunciation, grammar, or vocabulary, especially a variety of speech differing from the standard literary language or speech pattern of the culture in which it exists: Cockney is a dialect of English.
There was a 4 mm nodular opacity in the right lower lung. A ct scan of 10/06 showed linear scarring in both lungs but no mention of nodules. A chest xray in 4/2007 showed a round density in the right perihilar region.
For a given medium at a given frequency, the opacity has a numerical value that may range between 0 and infinity, with units of length 2 /mass. Opacity in air pollution work refers to the percentage of light blocked instead of the attenuation coefficient (aka extinction coefficient) and varies from 0% light blocked to 100% light blocked: