role vs name part

role and name part both are nouns.

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

As nouns, name part is a hyponym of role; that is, name part is a word with a more specific, narrower meaning than role:

Other hyponyms of role include bit part, minor role, heavy, hero, ingenue, title role, heroine, baddie, villain.

role (noun)	name part (noun)
the actions and activities assigned to or required or expected of a person or group	the role of the character after whom the play is named
normal or customary activity of a person in a particular social setting
what something is used for
an actor's portrayal of someone in a play