pacifier vs mediator

pacifier and mediator both are nouns.

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

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

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

pacifier (noun)	mediator (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