Traditional European business (5)
I believe the answer is:
trade
'business' is the definition.
(trade is a kind of business)
'traditional european' is the wordplay.
'traditional' becomes 'trad' (abbreviation - especially in music 'trad jazz').
'european' becomes 'e' (abbreviation e.g. EU).
'trad'+'e'='TRADE'
(Other definitions for trade that I've seen before include "Business - deal" , "groundsman?" , "Commercial dealings" , "Buy and sell, barter" , "Give and receive (blows)" .)