skiagram vs shadowgraph

skiagram and shadowgraph both are nouns.

Word	Noun	Adjective	Verb	Adverb
skiagram	Yes	No	No	No
shadowgraph	Yes	No	No	No

As nouns, skiagram and shadowgraph are synonyms defined as:

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

Other synonyms of skiagram include radiogram, radiograph, skiagraph.

skiagram (noun)	shadowgraph (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)