Consumed drinks on mountain ridge (5)
I believe the answer is:
arete
'mountain ridge' is the definition.
(I've seen this before)
'consumed drinks on' is the wordplay.
'consumed' becomes 'ate' (to eat is to consume food).
'drinks' means one lot of letters goes inside another (inserted letters are consumed or drunk).
'on' becomes 're' (regarding).
'ate' going around 're' is 'ARETE'.
(Other definitions for arete that I've seen before include "Glacial ridge" , "feature of range" , "Narrow mountain ridge - eater (anag)" , "part of mountain range" , "Sharp ridge on mountain, with a tree" .)