(often followed by `of') a large number or amount or extent
"a batch of letters"
"a deal of trouble"
"a lot of money"
"he made a mint on the stock market"
"see the rest of the winners in our huge passel of photos"
"it must have cost plenty"
"a slew of journalists"
"a wad of money"
An elevation of land of considerable dimensions rising more or less abruptly, forming a conspicuous figure in the landscape, usually having a small extent of surface at its summit.
"The museum recently restored its most famous mountain to run on the heritage railway line."
a steam locomotive of the 4-8-2 wheel arrangement.
In plain English: A mountain is a very tall hill that rises high above the land around it.
"We hiked up the mountain to watch the sunset."
Usage: Use mountain to describe a very large natural elevation of land that rises abruptly from surrounding terrain. Do not use this word for a steam locomotive, which is historically known as a Mountain type but should be referred to by its specific railway classification instead.
A placename
"We are hiking up Mount Everest today, which is a popular mountain for climbers from around the world."
A village in North Dakota, United States.
"The old family photo shows my great-grandfather standing proudly in front of Mountain when he first arrived to work on the railroad there a century ago."
The word "mountain" entered English from the French, derived ultimately from a Proto-Indo-European root meaning "to project or stick out." This borrowing replaced the native Old English terms beorg and dūn, as well as another Latin-derived word, munt.