Source : Webster's Revised Unabridged Dictionary (1913)

Fluctuant \Fluc"tu*ant\ (?; 135), a. [L. fluctuans, p. pr. of
   fluctuare. See {Fluctuate}.]
   1. Moving like a wave; wavering; (Med.) showing undulation or
      fluctuation; as, a fluctuant tumor.

   2. Floating on the waves. [Obs.] --Bacon.