Mycenaean civilisation vs British spelling

Mycenaean civilisation and British spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
Mycenaean civilisation	Yes	No	No	No
British spelling	Yes	No	No	No

Mycenaean civilisation (noun)	British spelling (noun)
the late bronze-age culture of Mycenae that flourished 1400-1100 BC	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')