ugjennomsiktig

Ugjenommsiktig is a Norwegian adjective describing a material or surface that does not permit light to pass through, i.e., opaque. It stands in opposition to gjennomsiktig, which means transparent, and to halvgjennomsiktig, used for semi-transparent materials. The classification of a substance as ugjenommsiktig depends on factors such as pigment concentration, thickness, surface texture, and any coatings that absorb or reflect light. In practice, many everyday materials—such as painted metal, certain ceramics, dense plastics, and dark fabrics—are described as ugjenommsiktig.

In physical contexts, ugjenommsiktig materials block almost all visible light and thus obscure objects on the opposite side. Some materials may be ugjenommsiktig for specific wavelengths while remaining partially transparent in others, but the term is most commonly applied to visible-light properties. The degree of opacity can vary with angle of view and lighting conditions.

Metaphorically, ugjenommsiktig is also used to describe processes, systems, or policies that lack transparency, meaning information is not readily accessible or understandable to outsiders. In this sense, it is contrasted with åpenhet or transparens, which refer to openness and clarity in governance or communication.

Etymology: the prefix u- negates gjennomsiktig (transparent), forming ugjenommsiktig. Related noun forms include ugjenommsiktighet (opaqueness) and gjennomsiktighet (transparency).