isotope vs radioisotope

isotope and radioisotope both are nouns.

Word	Noun	Adjective	Verb	Adverb
isotope	Yes	No	No	No
radioisotope	Yes	No	No	No

As nouns, radioisotope is a hyponym of isotope; that is, radioisotope is a word with a more specific, narrower meaning than isotope:

isotope: one of two or more atoms with the same atomic number but with different numbers of neutrons
radioisotope: a radioactive isotope of an element; produced either naturally or artificially

Other hyponyms of isotope include deuterium, heavy hydrogen.

isotope (noun)	radioisotope (noun)
one of two or more atoms with the same atomic number but with different numbers of neutrons	a radioactive isotope of an element; produced either naturally or artificially