flotāˈtion noun

1. The act of floating
2. The science of floating bodies
3. The act of starting a business, esp a limited liability company, by drawing up various documents and raising capital by selling shares
4. (also froth flotation) a method of separating ore from the rock in which it is embedded by forming a froth, the ore particles clinging to the bubbles

flotation therapy noun (medicine)

An alternative therapy for stress in which the patient floats for about an hour in a sealed salt-water-filled capsule (a flotation tank or float tank), sometimes with music piped in

plane or line of flotation

The plane or line in which the horizontal surface of a fluid cuts a body floating in it