intermediator vs intermediary

intermediator and intermediary both are nouns.

Word	Noun	Adjective	Verb	Adverb
intermediator	Yes	No	No	No
intermediary	Yes	No	No	No

As nouns, intermediator and intermediary are synonyms defined as:

intermediator and intermediary: a negotiator who acts as a link between parties

Other synonyms of intermediator include go-between, intercessor, mediator.

intermediator (noun)	intermediary (noun)
a negotiator who acts as a link between parties	a negotiator who acts as a link between parties