small person vs mortal

small person and mortal both are nouns.

Word	Noun	Adjective	Verb	Adverb
small person	Yes	No	No	No
mortal	Yes	Yes	No	No

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

small person: a person of below average size
mortal: a human being; person, singular, assertive existential pronoun; pronoun, person, singular; quantifier: assertive existential

Other hypernyms of small person include individual, person, somebody, someone, soul.

small person (noun)	mortal (noun)
a person of below average size	a human being; person, singular, assertive existential pronoun; pronoun, person, singular; quantifier: assertive existential

small person (adjective)	mortal (adjective)
	subject to death
	unrelenting and deadly
	involving loss of divine grace or spiritual death
	causing or capable of causing death