Nawab's new form of address in Africa (5)
I believe the answer is:
bwana
'form of address in africa' is the definition.
The definition suggests a singular noun which matches the answer.
'nawab's new' is the wordplay.
'new' is an anagram indicator.
'nawab' is an anagram of 'BWANA'.
Can you help me to learn more?
(Other definitions for bwana that I've seen before include "African boss" , "master in Africa" , "African form of address" , "Master's" , "Master (Afrikaans)" .)