Source : Webster's Revised Unabridged Dictionary (1913)

Lyssa \Lys"sa\ (l[i^]s"s[.a]), n. [NL. See {Lytta}.] (Med.)
   Hydrophobia.

   Note: The plural (Lyss[ae]) has been used to signify the
         pustules supposed to be developed under the tongue in
         hydrophobia.

Source : WordNet®

lyssa
     n : an acute viral disease of the nervous system of warm-blooded
         animals (usually transmitted by the bite of a rabid
         animal); rabies is fatal if the virus reaches the brain
         [syn: {rabies}, {hydrophobia}, {madness}]