A person who acts independently or remains neutral, especially in politics. often Mugwump A Republican who bolted the party in 1884,. ??? ???mugwump: Definition from ???, mugwumps. mugwumps (m??g'w??mps") [key], slang term in U.S. political history for the Republicans who in 1884 deserted their party nominee, James G. Blaine, to vote for the Democratic nominee, Grover Cleveland.