Effects coming from middle of arena, say (6)
I believe the answer is:
estate
'effects' is the definition.
(someone's estate is their personal effects)
'middle of arena say' is the wordplay.
'middle of' says to take the centre.
'say' becomes 'state' (synonyms).
The middle letter of 'arena' is 'e'.
'e'+'state'='ESTATE'
'coming from' acts as a link.
(Other definitions for estate that I've seen before include "Car with big luggage area" , "Industrial area" , "Family land" , "Piece of land with a lot of houses" , "Everything one owns -- tea set (anag)" .)