authoritative vs mandate

authoritative is not a noun while mandate is a noun.

Word	Noun	Adjective	Verb	Adverb
authoritative	No	Yes	No	No
mandate	Yes	No	Yes	No

authoritative (noun)	mandate (noun)
	the commission that is given to a government and its policies through an electoral victory
	a document giving an official instruction or command
	a territory surrendered by Turkey or Germany after World War I and put under the tutelage of some other European power until they are able to stand by themselves

authoritative (adjective)	mandate (adjective)
endowed with authority
having authority or ascendancy or influence
of recognized authority or excellence