title role vs theatrical role

title role and theatrical role both are nouns.

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

As nouns, theatrical role is a hypernym of title role; that is, theatrical role is a word with a broader meaning than title role:

Other hypernyms of title role include character, part, persona, role.

title role (noun)	theatrical role (noun)
the role of the character after whom the play is named	an actor's portrayal of someone in a play