British spelling vs operating theatre

British spelling and operating theatre both are nouns.

Word	Noun	Adjective	Verb	Adverb
British spelling	Yes	No	No	No
operating theatre	Yes	No	No	No

British spelling (noun)	operating theatre (noun)
English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')	a room in a hospital equipped for the performance of surgical operations