Doctor wearing a ring in pulpit (4)
I believe the answer is:
ambo
'pulpit' is the definition.
(synonyms)
'doctor wearing a ring' is the wordplay.
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus).
'wearing' indicates putting letters inside.
'ring' becomes 'O' (O is the shape of a ring).
'a'+'o'='ao'
'mb' placed into 'ao' is 'AMBO'.
'in' is the link.
(Other definitions for ambo that I've seen before include "desk" , "Old reading-desk" , "Early form of pulpit" , "Early Christian pulpit" , "Raised pulpit" .)