theatrical role vs portrayal

theatrical role and portrayal both are nouns.

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

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

theatrical role: an actor's portrayal of someone in a play
portrayal: acting the part of a character on stage; dramatically representing the character by speech and action and gesture

Other hypernyms of theatrical role include characterization, enactment, personation.

theatrical role (noun)	portrayal (noun)
an actor's portrayal of someone in a play	representation by drawing or painting etc
	acting the part of a character on stage; dramatically representing the character by speech and action and gesture
	any likeness of a person, in any medium
	a representation by picture or portraiture
	a word picture of a person's appearance and character