skiagraph vs radiogram

skiagraph and radiogram both are nouns.

Word	Noun	Adjective	Verb	Adverb
skiagraph	Yes	No	No	No
radiogram	Yes	No	No	No

As nouns, skiagraph and radiogram are synonyms defined as:

skiagraph and radiogram: a photographic image produced on a radiosensitive surface by radiation other than visible light (especially by X-rays or gamma rays)

Other synonyms of skiagraph include radiograph, shadowgraph, skiagram.

skiagraph (noun)	radiogram (noun)
a photographic image produced on a radiosensitive surface by radiation other than visible light (especially by X-rays or gamma rays)	a photographic image produced on a radiosensitive surface by radiation other than visible light (especially by X-rays or gamma rays)
	a message transmitted by wireless telegraphy