clonic

from WordNet (r) 3.0 (2006)

clonic
    adj 1: of or relating to abnormal neuromuscular activity
           characterized by rapidly alternating muscle contraction
           and relaxation; "clonic spasm"

from The Collaborative International Dictionary of English v.0.48

Clonic \Clon"ic\, a. [Gr. klo`nos a violent, confused motion;
   cf. F. clonique.] (Med.)
   Having an irregular, convulsive motion. --Dunglison.
   [1913 Webster]

   {Clonic spasm}. (Med.) See under {Spasm}.
      [1913 Webster]