The Collaborative International Dictionary of English v.0.48:

Ogre \O"gre\ ([=o]"g[~e]r), n. [F., fr. Sp. ogro, fr. L. Orcus
   the god of the infernal regions; also, the lower world,
   hell.]
   An imaginary monster, or hideous giant of fairy tales, who
   lived on human beings; hence, any frightful giant; a cruel
   monster.
   [1913 Webster]

         His schoolroom must have resembled an ogre's den.
                                                  --Maccaulay.
   [1913 Webster]

WordNet (r) 3.0 (2006):

ogre
    n 1: a cruel wicked and inhuman person [syn: monster, fiend,
         devil, demon, ogre]
    2: (folklore) a giant who likes to eat human beings