radioisotope vs isotope

radioisotope and isotope both are nouns.

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

As nouns, isotope is a hypernym of radioisotope; that is, isotope is a word with a broader meaning than radioisotope:

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

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