What is the difference between a hill, k**b, knoll and mountain?

Question

I've never really seen any criteria that decidedly says at what point a mound of rock and dirt ceases to be a hill and becomes a mountain etc.

Answer 1

The distinction between a hill and a mountain is unclear and largely subjective, but a hill is generally somewhat lower and less steep than a mountain.  A mountain is usually steeper and taller than a hill. Mountains are often thought of as being a hill of over 600 metres (about 2,000 feet), but this definition is not the same in every country.  A k**b is a prominent rounded hill or mountain.  A knoll is a small natural hill.