angiocardiogram vs X-ray

angiocardiogram and X-ray both are nouns.

Word	Noun	Adjective	Verb	Adverb
angiocardiogram	Yes	No	No	No
X-ray	Yes	No	No	No

As nouns, X-ray is a hypernym of angiocardiogram; that is, X-ray is a word with a broader meaning than angiocardiogram:

angiocardiogram: a series of X rays representing the action of the heart and its blood vessels after the injection of a radiopaque substance
X-ray: a radiogram made by exposing photographic film to X rays; used in medical diagnosis

Other hypernyms of angiocardiogram include roentgenogram, X-ray photograph, X-ray picture, X ray.

angiocardiogram (noun)	X-ray (noun)
a series of X rays representing the action of the heart and its blood vessels after the injection of a radiopaque substance	a radiogram made by exposing photographic film to X rays; used in medical diagnosis
	electromagnetic radiation of short wavelength produced when high-speed electrons strike a solid target