rabid

Short definition from Wiktionary

Adjective

1. 1
   Affected with rabies.
2. 2
   Of or pertaining to rabies, or hydrophobia.
3. 3
   Furious; raging; extremely violent.
4. 4
   Very extreme, unreasonable, or fanatical in opinion; excessively zealous.

Noun

1. 1
   A human or animal infected with rabies.
2. 2
   Someone who is fanatical in opinion.