The Collaborative International Dictionary of English v.0.48:

Superfluitant \Su`per*flu"i*tant\, a. [L. super above +
   fluitans, p. pr. of fluitare intensive fr. fluere to flow.]
   Floating above or on the surface. [Obs.] --Sir T. Browne. --
   Su`per*flu"i*tance, n. [Obs.]
   [1913 Webster]