the person that is used by the speaker of an utterance in referring to anything or to anyone other than the speaker or the one or ones being addressed.
2.
a linguistic form or the group of linguistic forms referring to this grammatical person, as certain verb forms, pronouns, etc.:
“He goes” contains a pronoun and a verb form in the third person.
3.
in or referring to such a grammatical person or linguistic form:
“He,” “she,” “it,” and “they” are third person pronouns, singular and plural, nominative case.
Origin
1580-90
British Dictionary definitions for third person
third person
noun
1.
a grammatical category of pronouns and verbs used when referring to objects or individuals other than the speaker or his addressee(s)