Source : Webster's Revised Unabridged Dictionary (1913)

Ergotism \Er"go*tism\, n. [F. ergotisme, fr. L. ergo.]
   A logical deduction. [Obs.] --Sir T. Browne.

Ergotism \Er"got*ism\, n. [From {Ergot}, n.; cf. F. ergotisme.]
   (Med.)
   A diseased condition produced by eating rye affected with the
   ergot fungus.

Source : WordNet®

ergotism
     n : poisoning by ingestion of ergot-infected grain products;
         characterized by thirst and diarrhea and nausea and
         craming and vomiting and abnormal cardiac rhythms; in
         severe cases it can cause seizures and gangrene of the
         limbs