(1):

(n.) An instrument for measuring and recording solar radiation.

(2):

(n.) An image or picture produced upon a sensitive surface, as of a photographic plate, by some form of radiation other than light, as the Rontgen rays, radium rays, etc.; esp., a picture of opaque objects traversed by the rays; a skiagraph.

(3):

(v. t.) To make a radiograph of.

(4):

(n.) A picture produced by the Rontgen rays upon a sensitive surface, photographic or fluorescent, especially a picture of opaque objects traversed by the rays.