a fluid that exhibits frictionless flow, very high heat conductivity, and other unusual physical properties, helium below 2.186 K being the only known example.
su·per·flu·id (sōō'pər-flōō'ĭd) n. A fluid, such as a liquid form of helium, exhibiting a frictionless flow at temperatures close to absolute zero. su'per·flu·id'i·ty (-flōō-ĭd'ĭ-tē) n.
superfluid (s'pər-fl'ĭd) Pronunciation Key
A fluid, such as liquid helium, that flows with little or no friction at temperatures close to absolute zero.