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"