role vs title role

role and title role both are nouns.

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

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

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

role (noun)	title role (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