Patience very drunk with Yorkshire banker (9)
I believe the answer is:
solitaire
'patience' is the definition.
(I know that patience can be written as solitaire)
'very drunk with yorkshire banker' is the wordplay.
'very' becomes 'so' (both can mean 'extremely').
'drunk' becomes 'lit' (I've seen this in another clue).
'with' means one lot of letters go next to another.
'yorkshire banker' becomes 'aire' (the River Aire - a river is something that banks).
'so'+'lit'+'aire'='SOLITAIRE'
(Other definitions for solitaire that I've seen before include "Game for one person - single gem" , "recluse" , "One-gem ring; one-player game" , "Patience; diamond" , "Patience of Americans" .)