Source : Webster's Revised Unabridged Dictionary (1913)

Mammoth \Mam"moth\, n. [Russ. m[^a]mont, m['a]mant, fr. Tartar
   mamma the earth. Certain Tartar races, the Tungooses and
   Yakoots, believed that the mammoth worked its way in the
   earth like a mole.] (Zo["o]l.)
   An extinct, hairy, maned elephant ({Elephas primigenius}), of
   enormous size, remains of which are found in the northern
   parts of both continents. The last of the race, in Europe,
   were coeval with prehistoric man.

   Note: Several specimens have been found in Siberia preserved
         entire, with the flesh and hair remaining. They were
         imbedded in the ice cliffs at a remote period, and
         became exposed by the melting of the ice.

Mammoth \Mam"moth\, a.
   Resembling the mammoth in size; very large; gigantic; as, a
   mammoth ox.

Source : WordNet®

mammoth
     adj : so exceedingly large or extensive as to suggest a giant or
           mammoth; "a gigantic redwood"; "gigantic
           disappointment"; "a mammoth ship"; "a mammoth
           multinational corporation" [syn: {gigantic}]

mammoth
     n : any of numerous extinct elephants widely distributed in the
         Pleistocene; extremely large with hairy coats and long
         upcurved tusks