The Collaborative International Dictionary of English v.0.48:

Rabid \Rab"id\ (r[a^]b"[i^]d), a. [L. rabidus, from rabere to
   rave. See Rage, n.]
   1. Furious; raging; extremely violent.
      [1913 Webster]

            The rabid flight
            Of winds that ruin ships.             --Chapman.
      [1913 Webster]

   2. Extreme, unreasonable, or fanatical in opinion;
      excessively zealous; as, a rabid socialist.
      [1913 Webster]

   3. Affected with the distemper called rabies; mad; as, a
      rabid dog or fox.
      [1913 Webster]

   4. (Med.) Of or pertaining to rabies, or hydrophobia; as,
      rabid virus.
      [1913 Webster]

WordNet (r) 3.0 (2006):

rabid
    adj 1: of or infected by rabies
    2: marked by excessive enthusiasm for and intense devotion to a
       cause or idea; "rabid isolationist" [syn: fanatic,
       fanatical, overzealous, rabid]

Moby Thesaurus II by Grady Ward, 1.0:

96 Moby Thesaurus words for "rabid":
   Dionysiac, abandoned, amok, bacchic, bellowing, berserk, bigoted,
   carried away, corybantic, crazed, crazy, delirious, demented,
   demoniac, deranged, desperate, distracted, ecstatic, enraged,
   enraptured, enthusiastic, extravagant, extreme, extremist, fanatic,
   fanatical, feral, ferocious, fierce, fighting mad, frantic,
   frenetic, frenzied, fulminating, fuming, furious, haggard,
   hog-wild, hopping mad, howling, hydrophobic, hysterical, in a rage,
   in a transport, in hysterics, infuriate, infuriated, inordinate,
   insane, intoxicated, irrational, keen, like one possessed, mad,
   madding, maenadic, maniac, maniacal, obsessed, orgasmic, orgiastic,
   overenthusiastic, overreligious, overzealous, perfervid, possessed,
   radical, raging, ramping, ranting, raving, raving mad, ravished,
   revolutional, revolutionary, revolutionist, roaring, roaring mad,
   running mad, running wild, savage, stark-raving mad, storming,
   transported, ultra, ultraist, ultrazealous, uncontrollable,
   unreasonable, unreasoning, violent, wild, wild-eyed, wild-looking,
   zealotic, zealous