demeanour vs demeanor

demeanour and demeanor both are nouns.

Word	Noun	Adjective	Verb	Adverb
demeanour	Yes	No	No	No
demeanor	Yes	No	No	No

As nouns, demeanour and demeanor are synonyms defined as:

demeanour and demeanor: (behavioral attributes) the way a person behaves toward other people

Other synonyms of demeanour include behavior, behaviour, conduct, deportment.

demeanour (noun)	demeanor (noun)
(behavioral attributes) the way a person behaves toward other people	(behavioral attributes) the way a person behaves toward other people