Alpine ground for one in mountainous territory (6)
I believe the answer is:
nepali
'one in mountainous territory' is the definition.
(in or relating to Nepal)
'alpine ground' is the wordplay.
'ground' indicates an anagram ('grind' the letters into a new form).
'alpine' is an anagram of 'NEPALI'.
'for' acts as a link.
(Other definitions for nepali that I've seen before include "one found in mountainous region" , "Asian national" , "Native of one Himalayan state" , "One from Katmandu" , "Language of Kathmandu" .)