The Collaborative International Dictionary of English v.0.48:

Spurge \Spurge\ (sp[^u]rj), v. t. [Etymol. uncertain.]
   To emit foam; to froth; -- said of the emission of yeast from
   beer in course of fermentation. [Obs.] --W. Cartright.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Spurge \Spurge\, n. [OF. espurge, F. ['e]purge, from OF.
   espurgier to purge, L. expurgare. See Expurgate, Purge.]
   (Bot.)
   Any plant of the genus Euphorbia. See Euphorbia.
   [1913 Webster]

   Spurge flax, an evergreen shrub (Daphne Gnidium) with
      crowded narrow leaves. It is a native of Southern Europe.


   Spurge laurel, a European shrub (Daphne Laureola) with
      oblong evergreen leaves.

   Spurge nettle. See under Nettle.

   Spurge olive, an evergreen shrub (Daphne oleoides) found
      in the Mediterranean region.
      [1913 Webster]

WordNet (r) 3.0 (2006):

spurge
    n 1: any of numerous plants of the genus Euphorbia; usually
         having milky often poisonous juice