Dad's put up with mum -- perhaps it's obvious (8)
I believe the answer is:
apparent
'obvious' is the definition.
(similar in meaning)
'dad's put up with mum perhaps' is the wordplay.
'dad' becomes 'pa' (both can mean one's father).
'put up' says the letters should be written backwards.
'with' is a charade indicator (letters next to each other).
'mum perhaps' becomes 'parent' (mum is a type of parent).
'pa' backwards is 'ap'.
'ap'+'parent'='APPARENT'
'it's' acts as a link.
(Other definitions for apparent that I've seen before include "Quite obvious and clear" , "Clearly visible" , "That may be seen" , "Obvious; seeming real" , "Writ large" .)