Boycott gloomy table (9)
I believe the answer is:
blacklist
'boycott' is the definition.
(I've seen this before)
'gloomy table' is the wordplay.
'gloomy' becomes 'black' (I've seen this before).
'table' becomes 'list' ().
'black'+'list'='BLACKLIST'
(Other definitions for blacklist that I've seen before include "(Put on a) roll of people considered untrustworthy" , "Boycott" , "Proscribe" , "Names of those banned, distrusted" .)