Scion, offspring (10)
I believe the answer is:
descendant
I believe this clue is a double definition.
'scion' is the first definition.
(I've seen this in another clue)
'offspring' is the second definition.
(I've seen this in another clue)
(Other definitions for descendant that I've seen before include "Future person in one's family line" , "Progeny" , "One from a long line" , "Later family member" , "Grandson maybe" .)