(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.
Both mirrors and carbon black are opaque. Opacity depends on the frequency of the light being considered. For instance, some kinds of glass, while transparent in the visual range, are largely opaque to ultraviolet light. More extreme frequency-dependence is visible in the absorption lines of cold gases. Opacity can be quantified in many ways; for example, see the article mathematical descriptions of opacity.