Fling daughter denied does for marriage (8)
I believe the answer is:
alliance
'for marriage' is the definition.
(I've seen this before)
'fling daughter denied' is the wordplay.
'fling' becomes 'dalliance' (I've seen this before).
'daughter' becomes 'd'.
'denied' is a deletion indicator.
'dalliance' with 'd' removed is 'ALLIANCE'.
'does' is the link.
(Other definitions for alliance that I've seen before include "League - treaty" , "Kind of partnership with canaille" , "A joining of forces" , "Confederation" , "match?" .)