pizza vs pizza pie

pizza and pizza pie both are nouns.

Word	Noun	Adjective	Verb	Adverb
pizza	Yes	No	No	No
pizza pie	Yes	No	No	No

As nouns, pizza and pizza pie are synonyms defined as:

pizza and pizza pie: Italian open pie made of thin bread dough spread with a spiced mixture of e.g. tomato sauce and cheese

pizza (noun)	pizza pie (noun)
Italian open pie made of thin bread dough spread with a spiced mixture of e.g. tomato sauce and cheese	Italian open pie made of thin bread dough spread with a spiced mixture of e.g. tomato sauce and cheese