See mountain in Webster's New World College Dictionary
noun
a natural raised part of the earth's surface, usually rising more or less abruptly, and larger than a hill
a chain or group of such elevations
a large pile, heap, or mound
a very large amount
adjective
of a mountain or mountains
situated, living, or used in the mountains
See mountain in American Heritage Dictionary 4
(mounˈtən)
noun
Abbr. Mt. or Mtn. A natural elevation of the earth's surface having considerable mass, generally steep sides, and a height greater than that of a hill.