So the umpire wants product of mine? (9)
I believe the answer is:
therefore
'so' is the definition.
(I've seen this before)
'the umpire wants product of mine?' is the wordplay.
'umpire' becomes 'ref' (I've seen this before).
'wants' says to put letters next to each other.
'product of mine?' becomes 'ore' (ore is a kind of mineral).
'the'+'ref'+'ore'='THEREFORE'
(Other definitions for therefore that I've seen before include "Thus" , "In consequence" , "It follows" , "has a triangular formation in maths?" , "Consequently - for that reason" .)