name part vs title role

name part and title role both are nouns.

Word	Noun	Adjective	Verb	Adverb
name part	Yes	No	No	No
title role	Yes	No	No	No

As nouns, name part and title role are synonyms defined as:

name part and title role: the role of the character after whom the play is named

name part (noun)	title role (noun)
the role of the character after whom the play is named	the role of the character after whom the play is named