The Collaborative International Dictionary of English v.0.48:

Anelectrotonus \An`e*lec*trot"o*nus\, n. [NL., fr. Gr. ? up + E.
   electrotonus.] (Physiol.)
   The condition of decreased irritability of a nerve in the
   region of the positive electrode or anode on the passage of a
   current of electricity through it. --Foster.
   [1913 Webster]