Verb- refers to the act of taking MDMA (ecstasy) and a strong narcotic (such as Oxycontin) simultaneously, producing a gentle, very carefree state of mind, not unlike a manatee drifting about the Florida Keys (before getting crushed by a speedboat full of bitches).
Carlos: "Hullo Xavier. Have you seen Pascual? He seems to be very slow."
Xavier: "Indeed. He's manatee flipping really hard."
Carlos: "We should engage in that soon."