matchmaker vs mediator

matchmaker and mediator both are nouns.

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

As nouns, mediator is a hypernym of matchmaker; that is, mediator is a word with a broader meaning than matchmaker:

Other hypernyms of matchmaker include go-between, intercessor, intermediary, intermediator.

matchmaker (noun)	mediator (noun)
someone who arranges (or tries to arrange) marriages for others	a negotiator who acts as a link between parties