Source : Webster's Revised Unabridged Dictionary (1913)

Amnesia \Am*ne"si*a\, n. [NL., fr. Gr. ?; 'a priv. + ? to
   remember.] (Med.)
   Forgetfulness; also, a defect of speech, from cerebral
   disease, in which the patient substitutes wrong words or
   names in the place of those he wishes to employ. --Quian.

Source : WordNet®

amnesia
     n : partial or total loss of memory; "he has a total blackout
         for events of the evening" [syn: {memory loss}, {blackout}]