Old country club by Yorkshire river (7)
I believe the answer is:
macedon
'old country' is the definition.
(ancient country)
'club by yorkshire river' is the wordplay.
'club' becomes 'mace' (mace can mean a club or stick).
'by' says to put letters next to each other.
'yorkshire river' becomes 'Don' (River Don in Yorkshire).
'mace'+'don'='MACEDON'
(Other definitions for macedon that I've seen before include "Philip's place" , "Alexander the Great's country" , "Philip's rule" , "Kingdom of Alexander the Great" .)