Source : Webster's Revised Unabridged Dictionary (1913)

Anaesthesia \An`[ae]s*the"si*a\, n. [NL., fr. Gr. ?; 'an priv. +
   ? feeling, ? to feel: cf. F. anesth['e]sie. See
   {[AE]sthetics}.] (Med.)
   Entire or partial loss or absence of feeling or sensation; a
   state of general or local insensibility produced by disease
   or by the inhalation or application of an an[ae]sthetic.

Source : WordNet®

anaesthesia
     n : loss of bodily sensation with or without loss of
         consciousness [syn: {anesthesia}]