unsure vs assurance

unsure is not a noun while assurance is a noun.

Word	Noun	Adjective	Verb	Adverb
unsure	No	Yes	No	No
assurance	Yes	No	No	No

unsure (noun)	assurance (noun)
	freedom from doubt; belief in yourself and your abilities
	a statement intended to inspire confidence
	a binding commitment to do or give or refrain from something
	a British term for some kinds of insurance

unsure (adjective)	assurance (adjective)
lacking or indicating lack of confidence or assurance
lacking self-confidence