Compass the mountaineer may be familiar with (5)

I believe the answer is:

range

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

'compass' is the definition.
(I know that compass can be written as range)

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

Can you help me to learn more?

(Other definitions for range that I've seen before include "Place to practise driving" , "Aga or mountain, perhaps?" , "Variety; scope" , "Scope; chain" , "Amplitude" .)

I've seen this clue in the Evening Standard.

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