Ticket for trophy having nothing on (6)
I believe the answer is:
coupon
'ticket' is the definition.
(I've seen this before)
'trophy having nothing on' is the wordplay.
'trophy' becomes 'cup' (cup is a kind of trophy).
'having' means one lot of letters goes inside another.
'nothing' becomes 'o' (O resembles 0).
'cup' placed around 'o' is 'coup'.
'coup'+'on'='COUPON'
'for' acts as a link.
(Other definitions for coupon that I've seen before include "means to buy goods" , "Token" , "Voucher or ticket" , "Entry form" , "betting slip" .)