demeanour vs behaviour

demeanour and behaviour both are nouns.

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

As nouns, demeanour and behaviour are synonyms defined as:

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

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

demeanour (noun)	behaviour (noun)
(behavioral attributes) the way a person behaves toward other people	manner of acting or controlling yourself
	(psychology) the aggregate of the responses or reactions or movements made by an organism in any situation
	(behavioral attributes) the way a person behaves toward other people
	the action or reaction of something (as a machine or substance) under specified circumstances