Chorus: again starts fine, then wet weather (7)
I believe the answer is:
refrain
'chorus' is the definition.
(I know that chorus can be written as refrain)
'again starts fine then wet weather' is the wordplay.
'again' becomes 're' (prefix meaning 'again').
'starts' suggests taking the first letters.
'then' says to put letters next to each other.
'wet weather' becomes 'rain' (rain is wet weather).
The first letter of 'fine' is 'f'.
're'+'f'+'rain'='REFRAIN'
(Other definitions for refrain that I've seen before include "Forbear from chorus?" , "Main theme" , "Chorus; desist" , "Kindly desist - from song?" , "Break off" .)