Weapon European held in fight (5)
I believe the answer is:
spear
'weapon' is the definition.
(I know that spear is a type of weapon)
'european held in fight' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'held in' indicates putting letters inside.
'fight' becomes 'spar' (sparring is a kind of fighting).
'e' placed into 'spar' is 'SPEAR'.
(Other definitions for spear that I've seen before include "Thrown weapon" , "stick" , "Stabbing, throwing, weapon" , "Weapon; asparagus stem" , "A bit of asparagus" .)