The Collaborative International Dictionary of English v.0.48:

Carnivorous \Car*niv"o*rous\, a. [L. carnivorus; caro, carnis,
   flesh + varare to devour.]
   Eating or feeding on flesh. The term is applied:
   (a) to animals which naturally seek flesh for food, as the
       tiger, dog, etc.;
   (b) to plants which are supposed to absorb animal food;
   (c) to substances which destroy animal tissue, as caustics.
       [1913 Webster] Carnose

WordNet (r) 3.0 (2006):

carnivorous
    adj 1: relating to or characteristic of carnivores; "the lion
           and other carnivorous animals"
    2: (used of plants as well as animals) feeding on animals;
       "carnivorous plants are capable of trapping and digesting
       small animals especially insects" [ant: herbivorous,
       insectivorous, omnivorous]

The Devil's Dictionary (1881-1906):

CARNIVOROUS, adj.  Addicted to the cruelty of devouring the timorous
vegetarian, his heirs and assigns.