Gloomy weather's ending -- love the hat! (8)
I believe the answer is:
sombrero
'the hat' is the definition.
(sombrero is a kind of hat)
'gloomy weather's ending love' is the wordplay.
'gloomy' becomes 'sombre' (I've seen this before).
'ending' says to take the final letters.
'love' becomes 'o' (In tennis, 'love' means 'zero').
The last letter of 'weather' is 'r'.
'sombre'+'r'+'o'='SOMBRERO'
(Other definitions for sombrero that I've seen before include "CLOTHING" , "Wide-brimmed Mexican hat" , "Covering up" , "headgear in parts of US" , "Mexican's hat" .)