pacifier vs go-between

pacifier and go-between both are nouns.

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

As nouns, go-between is a hypernym of pacifier; that is, go-between is a word with a broader meaning than pacifier:

Other hypernyms of pacifier include intercessor, intermediary, intermediator, mediator.

pacifier (noun)	go-between (noun)
device used for an infant to suck or bite on	a negotiator who acts as a link between parties
anything that serves to pacify
someone who tries to bring peace