A person who declares something; in card games like bridge, the player who made the contract and plays the hand.
From declare + -er agent suffix. The -er suffix is the most common English agent noun formation, far more productive than -or.
In bridge, the 'declarer' is one player trying to make the contract while everyone else opposes them—it's a position that requires both confidence and vulnerability. Interestingly, the same word works identically whether you're in a courtroom declaring testimony or in a card game declaring a bid.
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