deuterium vs isotope

deuterium and isotope both are nouns.

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

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

deuterium: an isotope of hydrogen which has one neutron (as opposed to zero neutrons in hydrogen)
isotope: one of two or more atoms with the same atomic number but with different numbers of neutrons

Other hypernyms of deuterium include hydrogen atom.

deuterium (noun)	isotope (noun)
an isotope of hydrogen which has one neutron (as opposed to zero neutrons in hydrogen)	one of two or more atoms with the same atomic number but with different numbers of neutrons