shadowgraph

noun

1. A shadow-picture; a radiograph or X-ray photograph; a sciagram.

   “`There you have its exemplification, a shadowgraph of vapour, penetrated by a single concrete element - my Mind.”

2. An optical technique of visualizing patterns of fluid flow by using differences in refractive index

verb

1. (transitive)To outline in a shadow-picture on a screen.
2. To take a picture by means of X-ray, radium, or similar source of actinic radiation.