radiology vs tracer

radiology and tracer both are nouns.

Word	Noun	Adjective	Verb	Adverb
radiology	Yes	No	No	No
tracer	Yes	No	No	No

radiology (noun)	tracer (noun)
(radiology) examination of the inner structure of opaque objects using X rays or other penetrating radiation	ammunition whose flight can be observed by a trail of smoke
the branch of medical science dealing with the medical use of X-rays or other penetrating radiation	(radiology) any radioactive isotope introduced into the body to study metabolism or other biological processes
	an instrument used to make tracings
	an investigator who is employed to find missing persons or missing goods