Wordnet 3.0
NOUN (1)
1. 
 a condition in which insufficient or no oxygen and carbon dioxide are exchanged on a ventilatory basis; 
 caused by choking or drowning or electric shock or poison gas; 
The Collaborative International Dictionary of English v.0.48:
Asphyxia \As*phyx"i*a\, Asphyxy \As*phyx"y\, n. [NL. asphyxia,
   fr. Gr. ?; 'a priv. + ? to throb, beat.] (Med.)
   Apparent death, or suspended animation; the condition which
   results from interruption of respiration, as in suffocation
   or drowning, or the inhalation of poisonous or irrespirable
   gases.
   [1913 Webster]
WordNet (r) 3.0 (2006):
asphyxia
    n 1: a condition in which insufficient or no oxygen and carbon
         dioxide are exchanged on a ventilatory basis; caused by
         choking or drowning or electric shock or poison gas