incertain vs authority

incertain is not a noun while authority is a noun.

Word	Noun	Adjective	Verb	Adverb
incertain	No	Yes	No	No
authority	Yes	No	No	No

incertain (noun)	authority (noun)
	the power or right to give orders or make decisions
	official permission or approval
	freedom from doubt; belief in yourself and your abilities
	an authoritative written work
	an administrative unit of government
	an expert whose views are taken as definitive
	(usually plural) persons who exercise (administrative) control over others

incertain (adjective)	authority (adjective)
lacking or indicating lack of confidence or assurance