Furnish European joke (5)
I believe the answer is:
equip
'furnish' is the definition.
(I know that equip is a more specific form of the action furnish)
'european joke' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'joke' becomes 'quip' (quipping is a kind of joking).
'e'+'quip'='EQUIP'
(Other definitions for equip that I've seen before include "Pique (anag.)" , "Outfit" , "Provide with suitable gear" , "Supply (with items)" , "Provide with items (for particular task)" .)