Mandarin tests Ms. Thurman (7)
I believe the answer is:
satsuma
'mandarin' is the definition.
(satsuma is a kind of mandarin)
'tests ms thurman' is the wordplay.
I cannot quite understand how this works, but
'tests' could be 'sats' (exams taken in UK schools) and 'sats' is present in the answer.
'thurman' could be 'uma' (I've seen this in another clue) and 'uma' is found within the answer.
No letters remain.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for satsuma that I've seen before include "As a must (anag)" , "Tangerine-like fruit" , "Kind of mandarin orange" , "Japanese province and small orange" , "Citrus fruit; Jap. pottery" .)