• An image produced on a radiosensitive surface, such as a photographic film or plate, when exposed to penetrating radiation, especially X-rays. Typically, the object to be analyzed is placed between the X-ray source and the film or plate, with the relative opacity determining the intensity of the shadows produced. Used, for instance, as a medical diagnostic technique, for ascertaining product defects, or in the quantitative analysis of materials. Also called shadowgram, skiagraph, skiagram, radiograph, X-ray (3), X-ray photograph, X-ray image, roentgenogram, or roentgenograph.
  • synonymshadowgram
  • synonymskiagram
  • synonymskiagraph


  • noun an old term for X-ray photograph