heterosexual person vs somebody

heterosexual person and somebody both are nouns.

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

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

heterosexual person: a person having a sexual orientation to persons of the opposite sex
somebody: a human being; person, singular, assertive existential pronoun; pronoun, person, singular; quantifier: assertive existential

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

heterosexual person (noun)	somebody (noun)
a person having a sexual orientation to persons of the opposite sex	a human being; person, singular, assertive existential pronoun; pronoun, person, singular; quantifier: assertive existential