unusual person vs somebody

unusual person and somebody both are nouns.

Word	Noun	Adjective	Verb	Adverb
unusual person	Yes	No	No	No
somebody	Yes	No	No	No

As nouns, somebody is a hypernym of unusual person; that is, somebody is a word with a broader meaning than unusual person:

unusual person: a person who is unusual
somebody: a human being; person, singular, assertive existential pronoun; pronoun, person, singular; quantifier: assertive existential

Other hypernyms of unusual person include individual, mortal, person, someone, soul.

unusual person (noun)	somebody (noun)
a person who is unusual	a human being; person, singular, assertive existential pronoun; pronoun, person, singular; quantifier: assertive existential