Dry in the fresh air a lot (4)
I believe the answer is:
arid
'dry' is the definition.
('arid' can be similar in meaning to 'dry')
'fresh air a lot' is the wordplay.
'fresh' indicates anagramming the letters.
'a lot' becomes 'd'.
'air' is an anagram of 'ari'.
'ari'+'d'='ARID'
'in the' is the link.
(Other definitions for arid that I've seen before include "Dry, devoid of interest" , "Drought-hit" , "Parched and barren" , "Dry and withered" , "(Of climate) dry" .)