Being greedy, snatch brandy though it's empty (6)

'being greedy' is the definition.
('grabby' can be a synonym of 'greedy')

'snatch brandy though it's empty' is the wordplay.
I cannot really see how this works, but
'snatch' could be 'grab' (synonyms) and 'grab' is found in the answer.
The remaining letters 'by' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?