Family member; not absolute (8)
I believe the answer is:
relative
I believe this is a double definition.
'family member' is the first definition.
(I've seen this before)
'not absolute' is the second definition.
('relative' is the opposite to 'absolute')
(Other definitions for relative that I've seen before include "Kinsman" , "Person connected by blood or marriage" , "Sort of pronoun" , "Person related by blood or marriage" , "Blood connection is not absolute" .)