The Collaborative International Dictionary of English v.0.48:

catatonic \cat`a*ton"ic\ adj.
   1. of or pertaining to catatonia; suffering from catatonia.
      [WordNet 1.5]

   2. appearing mentally stupefied, unresponsive, and
      motionless, or almost so; seemingly unaware of one's
      environment. [Colloq.]
      [PJC]

The Collaborative International Dictionary of English v.0.48:

catatonic \catatonic\ n.
   a person suffering from catatonia.
   [PJC]

WordNet (r) 3.0 (2006):

catatonic
    adj 1: characterized by catatonia especially either rigidity or
           extreme laxness of limbs

Moby Thesaurus II by Grady Ward, 1.0:

117 Moby Thesaurus words for "catatonic":
   abeyant, affectless, anesthetized, apathetic, arctic, asleep,
   autistic, blunt, brain-damaged, brain-injured, cataleptic,
   certifiable, chill, chilly, cold, cold as charity, cold-blooded,
   coldhearted, comatose, cool, dead, dispassionate, disturbed, doped,
   dopey, dormant, drugged, dull, emotionally dead, emotionless, flat,
   foul, frigid, frosted, frosty, frozen, groggy, half-conscious,
   heartless, heavy, icy, immovable, impassible, impassive,
   in abeyance, in suspense, inactive, inert, inexcitable,
   insusceptible, languid, languorous, latent, leaden, lifeless, logy,
   manic-depressive, mentally ill, mentally sick, narcotized,
   neurotic, nirvanic, nonemotional, objective, oblivious, obtuse,
   out, out cold, out of it, out of touch, paranoiac, paranoid,
   passionless, passive, phlegmatic, psychopathic, psychotic, schiz,
   schizoid, schizophrenic, schizy, sedentary, self-absorbed,
   semiconscious, senseless, slack, sleeping, sluggish, slumbering,
   smoldering, soulless, spaced out, spiritless, stagnant, standing,
   static, stoned, strung out, suspended, tame, torpid,
   unaffectionate, unaroused, unconscious, unemotional, unfeeling,
   unimpassioned, unimpressionable, unloving, unpassionate,
   unresponding, unresponsive, unsusceptible, unsympathetic,
   untouchable, zonked, zonked out



The Jargon File (version 4.4.7, 29 Dec 2003):

catatonic
 adj.

    Describes a condition of suspended animation in which something is so 
    wedged or hung that it makes no response. If you are typing on a
    terminal and suddenly the computer doesn't even echo the letters back to
    the screen as you type, let alone do what you're asking it to do, then the
    computer is suffering from catatonia (possibly because it has crashed). ?
    There I was in the middle of a winning game of nethack and it went
    catatonic on me! Aaargh!? Compare buzz.


The Free On-line Dictionary of Computing (30 December 2018):

catatonic

    A description of a system that gives no indication
   that it is still working.  This might be because it has
   crashed without being able to give any error message or
   because it is busy but not designed to give any feedback.

   Compare buzz.

   [Jargon File]

   (2004-08-19)