succussion

noun
suc·​cus·​sion | \ sə-ˈkəsh-ən How to pronounce succussion (audio) \

Medical Definition of succussion

: the action or process of shaking or the condition of being shaken especially with violence:
a : a shaking of the body to ascertain if fluid is present in a cavity and especially in the thorax
b : the splashing sound made by succussion