Wonderful father returns to Samoan capital (4)
I believe the answer is:
apia
'samoan capital' is the definition.
(I've seen this in another clue)
'wonderful father returns' is the wordplay.
'wonderful' becomes 'ai' (I can't justify this - if you can you should believe this answer much more).
'father' becomes 'pa' (pa can mean dad or father).
'returns' shows that the letters should be reversed in order.
'ai'+'pa'='aipa'
'aipa' written backwards gives 'APIA'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for apia that I've seen before include "Pacific capital" , "Samoan port" , "Capital of Samoa" .)