Show bum whitish illegal booze (9)
I believe the answer is:
moonlight
'illegal booze' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'show bum whitish' is the wordplay.
'show bum' becomes 'moon' (I can't explain this - if you can you should give a lot more credence to this answer).
'whitish' becomes 'light' (similar in meaning).
'moon'+'light'='MOONLIGHT'
Can you help me to learn more?
(Other definitions for moonlight that I've seen before include "Work late" , "Lunar rays seen in thin gloom" , "piano piece" , "Burn the midnight oil" , "Secretly work" .)