Source : Webster's Revised Unabridged Dictionary (1913)

Phrenetic \Phre*net"ic\, Phrenetical \Phre*net"ic*al\, a. [L.
   phreneticus, Gr. ?, ?: cf. F. phr['e]n['e]tique. See
   {Frantic}, and cf. {Frenetic}.]
   Relating to phrenitis; suffering from frenzy; delirious; mad;
   frantic; frenetic. -- {Phre*net"ic*al*ly}, adv.

Phrenetic \Phre*net"ic\, n.
   One who is phrenetic. --Harvey.

Source : WordNet®

phrenetic
     adj : excessively agitated; transported with rage or other violent
           emotion; "frantic with anger and frustration";
           "frenetic screams followed the accident"; "a frenzied
           look in his eye" [syn: {frantic}, {frenetic}, {frenzied}]