(n.) A member of a committee.

Greek affiliate associate belonger brother card-carrier card-carrying member cardholder charter member clubber clubman clubwoman committeewoman comrade conventioneer conventioner conventionist district leader dues-paying member enlistee enrollee fellow fraternity man guildsman honorary member initiate insider joiner life member member national chairman one of us party chairman pledge political worker precinct captain precinct leader sister socius sorority girl sorority woman state chairman