The Collaborative International Dictionary of English v.0.48:

Manic \Man"ic\, a. [Gr. maniko`s mad, frenzied.] (Med.)
   Of or pert. to, or characterized by, mania, or excitement;
   frenzied; as, with manic energy.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

manic
    adj 1: affected with or marked by frenzy or mania uncontrolled
           by reason; "a frenzied attack"; "a frenzied mob"; "the
           prosecutor's frenzied denunciation of the accused"-
           H.W.Carter; "outbursts of drunken violence and manic
           activity and creativity" [syn: frenzied, manic]

Moby Thesaurus II by Grady Ward, 1.0:

84 Moby Thesaurus words for "manic":
   abnormal, agog, aquiver, aroused, atingle, atwitter,
   bereft of reason, brainsick, bursting, carried away, crackbrained,
   cracked, crazed, crazy, daft, deluded, demented,
   deprived of reason, deranged, disoriented, distraught, ebullient,
   effervescent, excited, exhilarated, fired, flighty, hallucinated,
   high, hopped up, impassioned, inflamed, insane, irrational,
   keyed up, lathered up, loco, lunatic, mad, maddened, mazed, mental,
   mentally deficient, meshuggah, moon-struck, moved, non compos,
   non compos mentis, not all there, not right, odd, of unsound mind,
   off, psycho, queer, ready to burst, reasonless, roused, senseless,
   sick, stark-mad, stark-staring mad, steamed up, stimulated,
   stirred, stirred up, strange, tetched, thrilled, tingling, tingly,
   touched, turned-on, unbalanced, unhinged, unsane, unsettled,
   unsound, wandering, whipped up, witless, worked up, wrought up,
   yeasty