Somewhat insult an Arab ruler’s wife (7)

I believe the answer is:
sultana
'ruler's wife' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'somewhat insult an arab' is the wordplay.
'somewhat' indicates the answer is hidden within the clue.
'SULTANA' is hidden in the letters of 'insult an arab'.
Can you help me to learn more?
(Other definitions for sultana that I've seen before include "Dry seedless grape" , "Shrivelled up" , "Wife of an Eastern potentate" , "concubine?" , "Sovereign's mother perhaps" .)
