Bury doctor alongside mysterious note (6)
I believe the answer is:
entomb
'bury' is the definition.
('entomb' can be a synonym of 'bury')
'doctor alongside mysterious note' is the wordplay.
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus**).
'alongside' is a charade indicator (letters next to each other).
'mysterious' is an anagram indicator.
'note' is an anagram of 'ento'.
'mb' after 'ento' is 'ENTOMB'.
(Other definitions for entomb that I've seen before include "Bury, place in a crypt" , "Cover - bury - hide" , "put to rest" , "shut up patients?" , "Place in a sepulchre" .)