Pop back again (3)
I believe the answer is:
dad
This clue might be a double definition.
'pop' is the first definition.
(synonyms)
'back again' is the second definition.
The answer and definition can be both people as well as being singular nouns.
Maybe there's a link between them I don't understand?
Can you help me to learn more?
(Other definitions for dad that I've seen before include "Popular father - a palindrome" , "Papa" , "Father, in short" , "Pa" , "Mum's mate" .)