Uncle Remus's brother (4)
I believe the answer is:
brer
This clue might be a double definition.
'uncle' is the first definition.
Both the definition and answer are singular nouns.
Perhaps you can see a link between them that I can't see?
'remus's brother' is the second definition.
(the Uncle Remus stories feature Br'er Rabbit etc)
Can you help me to learn more?
(Other definitions for brer that I've seen before include "Southern US relation" , "Relative" , "-- Rabbit, children's book character" , "US brother" , "and 21: Uncle Remus character" .)