endeavour vs British spelling

endeavour and British spelling both are nouns.

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

endeavour (noun)	British spelling (noun)
earnest and conscientious activity intended to do or accomplish something	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')
a purposeful or industrious undertaking (especially one that requires effort or boldness)

endeavour (verb)	British spelling (verb)
attempt by employing effort