intercessor vs intermediary

intercessor and intermediary both are nouns.

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

As nouns, intercessor and intermediary are synonyms defined as:

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

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

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