The Collaborative International Dictionary of English v.0.48:

Everest \Everest\ prop. n.
   the highest mountain in the world, situated in Nepal and
   Tibet; 29,028 feet high. proper name

   Note: Also used as a metaphor for a high mountain.

   Syn: Mount Everest, Mt. Everest.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Everest
    n 1: a mountain in the central Himalayas on the border of Tibet
         and Nepal; the highest mountain peak in the world (29,028
         feet high) [syn: Everest, Mount Everest, Mt. Everest]