DuckCorp Dico

Found one definition

1.                 From The Collaborative International Dictionary of English v.0.48:
                   
   
   
                   
                     
   Clonus \Clo"nus\, n. [NL., fr. Gr. klo`nos violent, confused
      motion.] (Med.)
      A series of muscular contractions due to sudden stretching of
      the muscle, -- a sign of certain neuropathies.
      [Webster 1913 Suppl.]