The Collaborative International Dictionary of English v.0.48:

Catalepsy \Cat"a*lep`sy\, Catalepsis \Cat`a*lep"sis\, n. [NL.
   catalepsis, fr. Gr. ? a seizure, fr. ? to seize upon; kata`
   down + ? to take, seize.] (Med.)
   A sudden suspension of sensation and volition, the body and
   limbs preserving the position that may be given them, while
   the action of the heart and lungs continues.
   [1913 Webster]

WordNet (r) 3.0 (2006):

catalepsy
    n 1: a trancelike state with loss of voluntary motion and
         failure to react to stimuli