Dad's double (4)
I believe the answer is:
papa
This clue might be a double definition.
'dad's' is the first definition.
(synonyms)
'double' is the second definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps there's a link between them I don't understand?
Can you help me to learn more?
(Other definitions for papa that I've seen before include "Mama's other half?" , "Daddy]" , "Dad" , "The old man" , "Comms code for 'P'" .)