Grandmother’s double refusal (4)
I believe the answer is:
nana
'grandmother's' is the definition.
(I've seen this before)
'double refusal' is the wordplay.
'double' indicates the doubling of some letters.
'refusal' becomes 'na' (I can't justify this - if you can you should believe this answer much more).
'na' duplicated is 'NANA'.
Can you help me to learn more?
(Other definitions for nana that I've seen before include "Zola's heroine" , "Fool; novel by Zola" , "Old woman" , "granny" , "Fool; Zola heroine" .)