Opacity
# Opacity

Opacity or opaque may refer to:

* Impediments to (especially, visible) light:
   * Opacities, absorption coefficients
   * Opacity (optics), property or degree of blocking the transmission of light
* Metaphors derived from literal optics:
   * In linguistics:
      * Opaque context, a term to describe the linguistic context of co-referential terms
      * Phonological opacity, a term in phonology
      * Semantic opacity, the opposite of semantic transparency
   * Opaque travel inventory, the market of selling unsold travel inventory at a discounted price
* Musical works:
   * Opacities (EP)
* Computer science:
   * Measure of obscuration of background by "painting" an image, e.g. alpha channel
   * Use of an opaque data type
   * Property attributed to data that can be interpreted only by using an external entity, e.g. magic cookie technology
   * Opaque binary blob, a network-engineering and computer-science technology
