Area with dry, rocky peak (6)
I believe the answer is:
sector
'area' is the definition.
(sector is a kind of area)
'with dry rocky peak' is the wordplay.
'with' means one lot of letters go next to another.
'dry' becomes 'sec' ('sec' can be similar in meaning to 'dry').
'rocky peak' becomes 'tor' (I've seen this before).
'sec' next to 'tor' is 'SECTOR'.
(Other definitions for sector that I've seen before include "Distinct part of an economy; area for military operations" , "Part of a pie chart" , "Corset for part of battle area" , "region" , "Distinct part (of, eg, economy)" .)