Dodgy dealer, perhaps, eccentric and quick-witted (9)
I believe the answer is:
cardsharp
'dodgy dealer perhaps' is the definition.
'eccentric and quick-witted' is the wordplay.
'eccentric' becomes 'card' (I've seen this before).
'and' is a charade indicator (letters next to each other).
'quick-witted' becomes 'sharp' ('sharp' can be a synonym of 'quick-witted').
'card'+'sharp'='CARDSHARP'
(Other definitions for cardsharp that I've seen before include "Cheater at the table" , "One who cheats with a pack" , "Swindler in game" , "Cheater at, say, poker" , "Dodgy dealer" .)