confidence vs uncertain

confidence is a noun but uncertain is not a noun.

Word	Noun	Adjective	Verb	Adverb
confidence	Yes	No	No	No
uncertain	No	Yes	No	No

confidence (noun)	uncertain (noun)
freedom from doubt; belief in yourself and your abilities
a secret that is confided or entrusted to another
a feeling of trust (in someone or something)
a state of confident hopefulness that events will be favorable
a trustful relationship

confidence (adjective)	uncertain (adjective)
	not established beyond doubt; still undecided or unknown
	lacking or indicating lack of confidence or assurance
	not certain to occur; not inevitable
	not established or confirmed
	ambiguous (especially in the negative)
	not consistent or dependable
	subject to change