Visible, person initially adopted by a mum or dad (8)
I believe the answer is:
apparent
'visible' is the definition.
(similar in meaning)
'person initially adopted by a mum or dad' is the wordplay.
'initially' indicates taking the first letters.
'adopted by' indicates putting letters inside (I've seen this in other clues).
'mum or dad' becomes 'parent' (I've seen this before).
The initial letter of 'person' is 'p'.
'a'+'parent'='aparent'
'p' put within 'aparent' is 'APPARENT'.
(Other definitions for apparent that I've seen before include "Seeming to be but not necessarily so" , "Seeming true; obvious" , "Seeming real or true" , "readily understood" , "cut , book written on a page" .)