a light flat object that floats on water and that you hold onto when learning to swim, or when you want to swim using only your legs, or only your arms

Megan is five and uses a kickboard during her swimming lesson. 梅根五岁，在游泳课上使用踢水板。

To exercise your lower body, hold a kickboard so that for a few lengths you are using only your legs. 为了锻炼下肢，你抓住踢水板，这样在一定距离内你只能用腿。