unsure vs timid

unsure is not a noun while timid is a noun.

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

As adjectives, unsure and timid are synonyms defined as:

Other synonyms of unsure include diffident, shy.

unsure (noun)	timid (noun)
	people who are fearful and cautious

unsure (adjective)	timid (adjective)
lacking or indicating lack of confidence or assurance	showing fear and lack of confidence
lacking self-confidence	lacking self-confidence
	lacking conviction or boldness or courage