Source : Webster's Revised Unabridged Dictionary (1913)

Resuscitator \Re*sus"ci*ta`tor\, n. [L.]
   One who, or that which, resuscitates.

Source : WordNet®

resuscitator
     n : a breathing apparatus used for resuscitation by forcing
         oxygen into the lungs of a person who has undergone
         asphyxia or arrest of respiration