The Collaborative International Dictionary of English v.0.48:

Frenetical \Fre*net"ic*al\, a.
   Frenetic; frantic; frenzied. -- Frenet"ic*al*ly, adv.

   Syn: frenetic; phrenetic.
        [1913 Webster]

WordNet (r) 3.0 (2006):

frenetically
    adv 1: in a very agitated manner; as if possessed by an evil
           spirit [syn: demoniacally, frenetically]