Her mystic study (9)
I believe the answer is:
chemistry
'study' is the definition.
(chemistry is a kind of study)
'her mystic' is the wordplay.
'her mystic' anagrams to 'CHEMISTRY'.
But, I am unsure how the anagram is indicated.
Can you help me to learn more?
(Other definitions for chemistry that I've seen before include "What may be taught at school" , "scientific discipline" , "Science - mutual attraction" , "Stinks (school slang)" , "Scientific study of substances, or sexual attraction" .)