go-between vs intermediary

go-between and intermediary both are nouns.

Word	Noun	Adjective	Verb	Adverb
go-between	Yes	No	No	No
intermediary	Yes	No	No	No

As nouns, go-between and intermediary are synonyms defined as:

go-between and intermediary: a negotiator who acts as a link between parties

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

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