buckjumper

buckjumperbuckjumper[ˈbʌkˌdʒʌmpə]n.1.■跃腾使骑者跌落的马匹

buckjumper['bʌk,dʒʌmpə]n.1.■惯于猛然弓背跃起的马(或驴等)；劣马2.■(弓背)跳跃者