buckjump Syllabification: (buck·jump)Pronunciation: /ˈbəkˌjəmp/ AustralianDefinition of buckjump verb [no object] (of a horse) jump vertically with the head lowered, back arched, and legs drawn together in an attempt to unseat the rider. noun [often as modifier] an act or display of buckjumping:a buckjump riderDerivatives buckjumper noun buckjump in other Oxford dictionaries Definition of buckjump in the British & World English dictionary