movie theatre vs movie theater

movie theatre and movie theater both are nouns.

Word	Noun	Adjective	Verb	Adverb
movie theatre	Yes	No	No	No
movie theater	Yes	No	No	No

As nouns, movie theatre and movie theater are synonyms defined as:

Other synonyms of movie theatre include cinema, movie house, picture palace.

movie theatre (noun)	movie theater (noun)
a theater where films are shown	a theater where films are shown