Woman grabbing doctor's instrument (7)
I believe the answer is:
marimba
'instrument' is the definition.
(marimba is a kind of instrument)
'woman grabbing doctor's' is the wordplay.
'woman' becomes 'maria' (**).
'grabbing' is an insertion indicator.
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus).
'maria' enclosing 'mb' is 'MARIMBA'.
(Other definitions for marimba that I've seen before include "Xylophone-like instrument from Africa" , "Latin American instrument like a xylophone" , "Xylophone-like instr." , "African xylophone" , "Deep toned percussion instrument" .)