Yea and nay are words that are most commonly used in formal voting. Yea means "yes" or signals an affirmative vote, while nay means "no" or signals a negative vote. Yay, on the other hand, is an interjection that expresses "triumph, excitement, or joy". It is not used for voting and is a different word from yea. Nay can also be used to signal denial, refusal, or a negative reply. Yea and nay are homophones, meaning they are pronounced the same way but have different meanings.