Barn"burn`er (?), n. [So called in allusion to the fable of the man who burned his barn in order to rid it of rats.] A member of the radical section of the Democratic party in New York, about the middle of the 19th century, which was hostile to extension of slavery, public debts, corporate privileges, etc., and supported Van Buren against Cass for president in 1848; -- opposed to Hunker. [Political Cant, U. S.]

Barn"burn`er (?), n. [So called in allusion to the fable of the man who burned his barn in order to rid it of rats.] A member of the radical section of the Democratic party in New York, about the middle of the 19th century, which was hostile to extension of slavery, public debts, corporate privileges, etc., and supported Van Buren against Cass for president in 1848; -- opposed to Hunker. [Political Cant, U. S.]

• Liberal faction of the New York state United States Democratic Party in the mid 19th century.
  
• (idiom) An extremely exciting or successful event.
  
• One who burns down a barn.