Lover castigated about being dull (8)
I believe the answer is:
overcast
'being dull' is the definition.
(I've seen this before)
'lover castigated about' is the wordplay.
'about' says the answer is hidden in the clue.
'OVERCAST' is hidden in the letters of 'lover castigated'.
(Other definitions for overcast that I've seen before include "Overacts, being gloomy" , "Not very bright" , "(Of weather) cloudy, dull" , "Gloomy like cloudy sky" , "Sunless" .)