Ride around top of road: it's not so wet (5)
I believe the answer is:
drier
'not so wet' is the definition.
('dry' can be the opposite of 'wet' so perhaps 'drier' is reasonable for 'not so wet')
'ride around top of road' is the wordplay.
'around' indicates anagramming the letters.
'top of' suggests taking the first letters.
The initial letter of 'road' is 'r'.
'ride' anagrammed gives 'drie'.
'drie'+'r'='DRIER'
'it's' acts as a link.
(Other definitions for drier that I've seen before include "Laundry machine" , "Airer" , "Machine which removes water" , "See 1" , "Machine giving spin" .)