azo radical vs chemical group

azo radical and chemical group both are nouns.

Word	Noun	Adjective	Verb	Adverb
azo radical	Yes	No	No	No
chemical group	Yes	No	No	No

As nouns, chemical group is a hypernym of azo radical; that is, chemical group is a word with a broader meaning than azo radical:

azo radical: the bivalent group -N=N- united to two hydrocarbon groups
chemical group: (chemistry) two or more atoms bound together as a single unit and forming part of a molecule

Other hypernyms of azo radical include group, radical.

azo radical (noun)	chemical group (noun)
the bivalent group -N=N- united to two hydrocarbon groups	(chemistry) two or more atoms bound together as a single unit and forming part of a molecule