Definition of superfluid in US English:

superfluid

noun

Physics
  • A liquid that flows without friction or viscosity.

    ‘superfluids can flow ceaselessly without any energy loss’

adjective

Physics
  • Having the property of flowing without friction or viscosity.

    ‘the sudden switch from liquid helium to superfluid helium’

Pronunciation

superfluid

/ˈsupərˌflu(w)əd//ˈso͞opərˌflo͞o(w)əd/