The Collaborative International Dictionary of English v.0.48:

Elutriate \E*lu"tri*ate\, v. t. [imp. & p. p. Elutriated; p.
   pr. & vb. n. Elutriating.] [L. elutriatus, p. p. of
   elutriare.]
   To wash or strain out so as to purify; as, to elutriate the
   blood as it passes through the lungs; to strain off or
   decant, as a powder which is separated from heavier particles
   by being drawn off with water; to cleanse, as by washing.
   [1913 Webster]