mediate vs mediator

mediate is not a noun while mediator is a noun.

Word	Noun	Adjective	Verb	Adverb
mediate	No	Yes	Yes	No
mediator	Yes	No	No	No

mediate (noun)	mediator (noun)
	a negotiator who acts as a link between parties

mediate (adjective)	mediator (adjective)
acting through or dependent on an intervening agency
being neither at the beginning nor at the end in a series

mediate (verb)	mediator (verb)
act between parties with a view to reconciling differences
occupy an intermediate or middle position or form a connecting link or stage between two others