Work the land on a distant mountain top (4)
I believe the answer is:
farm
'work the land' is the definition.
(I've seen this before)
'on a distant mountain top' is the wordplay.
'on' says to put letters next to each other.
'a distant' becomes 'far' (I've seen this before).
'top' indicates taking the first letters.
The initial letter of 'mountain' is 'm'.
'far'+'m' is 'FARM'.
(Other definitions for farm that I've seen before include "Productive land" , "Cold Comfort --" , "Agricultural worker" , "Rural workplace" , "Agricultural establishment" .)