Seeming to turn old man against old man? (8)
I believe the answer is:
apparent
'seeming' is the definition.
(synonyms)
'turn old man against old man?' is the wordplay.
'turn' is a reversal indicator.
'old man' becomes 'pa' (both can mean father).
'against' is a charade indicator (letters next to each other).
'old man?' becomes 'parent' (old man is a kind of parent).
'pa' back-to-front is 'ap'.
'ap'+'parent'='APPARENT'
'to' is the link.
(Other definitions for apparent that I've seen before include "cut , book written on a page" , "Evident, manifest" , "Ostensible, seeming" , "See 1" , "Seeming true; obvious" .)