Caucus : A meeting of the local members of a political party especially to select delegates to a convention or register preferences for candidates running for office.
Caucuses were the original method for selecting candidates but have decreased in number since the primary was introduced in the early 1900's. In states that hold caucuses a political party announces the date, time, and location of the meeting. Usually any voter registered member of the party may attend. At the caucus, delegates are chosen to represent the state's interests at the national party convention. Traditionally delegates are identified as favorable to a specific candidate or uncommitted. After discussion and debate an informal vote is taken to determine which delegates will be chosen.