Place in vault with space to add doctor (6)
I believe the answer is:
entomb
'place in vault' is the definition.
'space to add doctor' is the wordplay.
'space' becomes 'en'.
'add' means one lot of letters go next to another.
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus).
'en'+'to'+'mb'='ENTOMB'
'with' is the link.
(Other definitions for entomb that I've seen before include "Cover - bury - hide" , "put away body" , "Bury, place in a crypt" , "Put in a grave" , "shut up patients?" .)