A reflection prism used in optical instruments to alter the orientation of an image. It consists of a block of glass shaped as a right geometric prism with right-angled triangular end faces.

Glass with one smooth side and the other side formed into sharp-edged ridges so as to reflect the light that passes through, used at windows to throw the light into the interior.

A reflective optical prism containing a section where two faces meet at a 90° angle, resembling the roof of a building. Reflection from the two 90° faces returns an image that is flipped laterally across the axis where the faces meet.

A prism with a shallow angle between its input and output surfaces.

Synonym of accretionary wedge

(geometry) a prism whose cross section is an irregular polygon / (geometry) a solid that is like a prism but whose cross section is not (necessarily) a polygon