British spelling vs mum

British spelling and mum both are nouns.

Word	Noun	Adjective	Verb	Adverb
British spelling	Yes	No	No	No
mum	Yes	Yes	No	No

British spelling (noun)	mum (noun)
English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')	secrecy
	informal terms for a mother
	of China

British spelling (adjective)	mum (adjective)
	failing to speak or communicate etc when expected to