Medic in court blocking entrance (6)
I believe the answer is:
doctor
'medic' is the definition.
(I've seen this before)
'court blocking entrance' is the wordplay.
'court' becomes 'ct'.
'blocking' indicates putting letters inside.
'entrance' becomes 'door' (door is a kind of entrance).
'ct' put within 'door' is 'DOCTOR'.
'in' is the link.
(Other definitions for doctor that I've seen before include "Medical specialist" , "Tamper with - falsify - one of the 14 films" , "Ship's cook" , "Foster, Who, Jekyll or Livingstone" , "GP" .)