noun (n)

• the bridge player in contract bridge who wins the bidding and can declare which suit is to be trumps(noun.person)

  Synonym:
  contractor
  

  source: wordnet30
• someone who claims to speak the truth(noun.person)

  Example:
  A declarer of his intentions.
  

  Synonym:
  affirmer, asserter, asseverator, avower
  

  source: wordnet30
• One who makes known or proclaims; that which exhibits.(noun)

  source: webster1913