copresident

noun

1. Someone who serves as president together with someone else.

   “Public good nothing, replied the copresidents of the League of Women Voters of Chicago.”

   “In Budapest we came to an agreement that this would be an OSCE operation and that it would have two copresidents.”

   “On January 20, 2009, at precisely noon, the world will witness the inauguration of the forty-fourth president of the United States. As the chief justice administers the oath of office on the flag-draped podium in front of the U.S. Capitol, the first woman president, Hillary Rodham Clinton, will be sworn into office. By her side, smiling broadly and holding the family Bible, will be her chief strategist, husband, and copresident, William Jefferson Clinton.”

   “For a time, apparently, it was decided that Bobbie and Judy would be copresidents.”