Very dry, as a climate (4)
I believe the answer is:
arid
'very dry as a climate' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for arid that I've seen before include "Wadi may be this" , "Dry raid" , "flat" , "(Of climate) dry" , "Parched, waterless" .)