Coup/kuː/ Definition 1 of 3Pro Tip 1/3Forceful Change Refers to a sudden, forceful change in leadership, involving military or rebel involvement. The coup overthrew the dictatorship. Pro Tip 2/3Political Instability Often implies a period of political instability or conflict within a nation. Rumors of an impending coup spread fear among citizens. Pro Tip 3/3Not Always Successful A coup attempt might fail and can lead to consequences for the plotters. The soldiers who led the failed coup were arrested.