Photographer briefly a neighbour to Oscar (4)
I believe the answer is:
papa
'neighbour to oscar' is the definition.
I can't tell whether this definition defines the answer.
'photographer briefly a' is the wordplay.
'photographer briefly' becomes 'pap' (I am not sure about this - if you are sure you should believe this answer much more).
'pap'+'a'='PAPA'
Can you help me to learn more?
(Other definitions for papa that I've seen before include "Daddy]" , "one after Oscar" , "Dad" , "Pop" , "Father; P (radio comms.)" .)