moun·tain 
/ˈmaʊntn̩/ noun
plural moun·tains /ˈmaʊntn̩/ noun [count] 1 : an area of land that rises very high above the land around it and that is higher than a hill
▪ She watched the sun set behind the mountains. ▪ the Rocky Mountains ▪ He climbed the mountain. ▪ a cabin in the mountains ▪ They both like mountain climbing. ▪ mountain scenery ▪ a mountain range/lake ▪ a mountain man [=a man who lives in the mountains] — see color picture 2 : a very large amount of something
▪ We've received a mountain of mail. ▪ mountains of data
▪ She watched the sun set behind the mountains. ▪ the Rocky Mountains ▪ He climbed the mountain. ▪ a cabin in the mountains ▪ They both like mountain climbing. ▪ mountain scenery ▪ a mountain range/lake ▪ a mountain man [=a man who lives in the mountains] — see color picture
▪ We've received a mountain of mail. ▪ mountains of data
make a mountain out of a molehill — see molehill
