Buries old doctors on hospital department (7)
I believe the answer is:
entombs
'buries' is the definition.
('entomb' can be a synonym of 'bury')
'old doctors on hospital department' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'doctors' becomes 'MBs' (Bachelors of Medicine).
'on' means one lot of letters go next to another.
'hospital department' becomes 'ENT' (Ear, Nose and Throat department).
'o'+'mbs'='ombs'
'ombs' after 'ent' is 'ENTOMBS'.
(Other definitions for entombs that I've seen before include "sepulchres" , "Buries" .)