Toss coins for young family member (5)
I believe the answer is:
scion
'young family member' is the definition.
(I've seen this before)
'toss coins' is the wordplay.
'toss' indicates an anagram.
'coins' anagrammed gives 'SCION'.
'for' acts as a link.
(Other definitions for scion that I've seen before include "Offshoot" , "Descendent - heir" , "Coins (anag)" , "Younger member of a family" , "Issue" .)