Cooler not following escarpment (5)

I believe the answer is:

ridge

I'm a little stuck... Click here to teach me more about this clue!

'escarpment' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

(Other definitions for ridge that I've seen before include "Line of raised ground" , "Line where two upward sloping surfaces meet" , "Crest - spine" , "Long narrow crest" , "Long, narrow hilltop" .)

I've seen this clue in The Sun.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.