Mountain

noun
1.
a natural elevation of the earth’s surface rising more or less abruptly to a summit, and attaining an altitude greater than that of a hill, usually greater than 2000 feet (610 meters).
2.
a large mass of something resembling this, as in shape or size.
3.
a huge amount:
a mountain of incoming mail.
4.
(initial capital letter) a steam locomotive having a four-wheeled front truck, eight driving wheels, and a two-wheeled rear truck.
5.
Also called mountain wine. British Archaic. a sweet Malaga wine.
adjective
6.
of or relating to mountains:
mountain air.
7.
living, growing, or located in the mountains:
mountain people.
8.
resembling or suggesting a mountain, as in size.
Idioms
9.
make a mountain out of a molehill. molehill (def 2).
noun
1.

a natural upward projection of the earth’s surface, higher and steeper than a hill and often having a rocky summit
(as modifier): mountain people, mountain scenery
(in combination): a mountaintop

2.
a huge heap or mass: a mountain of papers
3.
anything of great quantity or size
4.
a surplus of a commodity, esp in the European Union: the butter mountain
5.
(Brit, informal) a mountain to climb, a serious or considerable difficulty or obstruction to overcome
6.
make a mountain out of a molehill, See molehill (sense 2)
noun
1.
the Mountain, an extremist faction during the French Revolution led by Danton and Robespierre
mountain
(moun’tən)
A generally massive and usually steep-sided, raised portion of the Earth’s surface. Mountains can occur as single peaks or as part of a long chain. They can form through volcanic activity, by erosion, or by uplift of the continental crust when two tectonic plates collide. The Himalayas, which are the highest mountains in the world, were formed when the plate carrying the landmass of India collided with the plate carrying the landmass of China.
see:

if the mountain won’t come to Muhammad
make a mountain out of a molehill