affirmer vs declarer

affirmer and declarer both are nouns.

Word	Noun	Adjective	Verb	Adverb
affirmer	Yes	No	No	No
declarer	Yes	No	No	No

As nouns, affirmer and declarer are synonyms defined as:

Other synonyms of affirmer include asserter, asseverator, avower.

affirmer (noun)	declarer (noun)
someone who claims to speak the truth	the bridge player in contract bridge who wins the bidding and can declare which suit is to be trumps
	someone who claims to speak the truth