Source : Webster's Revised Unabridged Dictionary (1913)

Hypnosis \Hyp*no"sis\, n.
   The condition of being hypnotized.

Hypnosis \Hyp*no"sis\, n. [NL., fr. Gr. ? sleep.] (Med.)
   Supervention of sleep.

Source : WordNet®

hypnosis
     n : a state that resembles sleep but that is induced by
         suggestion
     [also: {hypnoses} (pl)]