mandatary vs mandatory

mandatary and mandatory both are nouns.

Word	Noun	Adjective	Verb	Adverb
mandatary	Yes	No	No	No
mandatory	Yes	Yes	No	No

As nouns, mandatary and mandatory are synonyms defined as:

mandatary (noun)	mandatory (noun)
the recipient of a mandate	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
	the recipient of a mandate

mandatary (adjective)	mandatory (adjective)
	required by rule