ADJECTIVE (2)

1. relating to or associated with a coma;
- Example: "comatose breathing"
- Example: "comatose state"

2. in a state of deep and usually prolonged unconsciousness; unable to respond to external stimuli;
- Example: "a comatose patient"

The Collaborative International Dictionary of English v.0.48:

Comatose \Co"ma*tose`\ (? or ?; 277), a. [From Coma lethargy.]
   Relating to, or resembling, coma; drowsy; lethargic; as,
   comatose sleep; comatose fever.
   [1913 Webster]

WordNet (r) 3.0 (2006):

comatose
    adj 1: relating to or associated with a coma; "comatose
           breathing"; "comatose state"
    2: in a state of deep and usually prolonged unconsciousness;
       unable to respond to external stimuli; "a comatose patient"

Moby Thesaurus II by Grady Ward, 1.0:

106 Moby Thesaurus words for "comatose":
   Laodicean, Olympian, aloof, anesthetic, anesthetized, apathetic,
   asleep, benumbed, blah, blase, cataleptic, catatonic, cold, dead,
   dead asleep, deep asleep, desensitized, detached, disinterested,
   doped, dopey, dormant, dozy, dreamy, drowsy, drugged,
   drugged with sleep, dull, fast asleep, flaked-out, half asleep,
   half-conscious, heartless, heavy, heavy with sleep, heavy-eyed,
   hebetudinous, hopeless, impassible, in a stupor, indifferent,
   insensitive, insouciant, languid, lethargic, listless, napping,
   narcoleptic, narcose, narcotized, narcous, nirvanic, nodding,
   nonchalant, numb, numbed, oblivious, oscitant, out, out cold,
   out of it, passive, phlegmatic, pluckless, resigned, sedated,
   semiconscious, senseless, slack, sleep-drowned, sleep-drunk,
   sleep-filled, sleep-swollen, sleepful, sleeping, sleepy, sluggish,
   slumbering, slumberous, slumbery, snoozy, somnolent, soporific,
   sound asleep, spaced out, spiritless, spunkless, stoic, stoned,
   stretchy, strung out, stupefied, stupid, stuporose, stuporous,
   supine, torpid, uncaring, unconcerned, unconscious, uninterested,
   withdrawn, yawning, yawny, zonked, zonked out