Not bad; we, however, are gloomy (8)
I believe the answer is:
downbeat
'gloomy' is the definition.
(I've seen this before)
'not bad we however' is the wordplay.
'however' indicates anagramming the letters.
'not'+'bad'+'we'='notbadwe'
'notbadwe' anagrammed gives 'DOWNBEAT'.
'are' is the link.
(Other definitions for downbeat that I've seen before include "Dismal and depressing" , "Gloomy; laid-back" , "Casual" , "Low-key" , "Depressed - relaxed" .)