n.a dive in which the diver throws the feet forward and up to complete a half backward somersault and enters the water facing the diving board
英汉双解大词典
half gainer
1.
N(名词)
a type of dive in which the diver completes a half backward somersault to enter the water headfirst facing the diving board 跳水者头向前面对跳板完成半个后空翻后入水的跳水姿势