Source : Webster's Revised Unabridged Dictionary (1913)

Sprue \Sprue\, n. [Etymol. uncertain.]
   1. (Founding)
      (a) Strictly, the hole through which melted metal is
          poured into the gate, and thence into the mold.
      (b) The waste piece of metal cast in this hole; hence,
          dross.

   2. (Med.) Same as {Sprew}.

Source : WordNet®

sprue
     n : a chronic disorder that occurs in tropical and nontropical
         forms and in both children and adults; nutrients are not
         absorbed; symptoms include foul-smelling diarrhea and
         emaciation [syn: {tropical sprue}]