Convict, possibly, one taking tea round back of prison (6)
I believe the answer is:
inmate
'convict' is the definition.
(I know that convict can be written as inmate)
'one taking tea round back of prison' is the wordplay.
'one' becomes 'i' (Roman numeral).
'taking' means one lot of letters go next to another.
'tea' becomes 'mate' (South American hot drink).
'round' means one lot of letters goes inside another.
'back of prison' becomes 'n' (I can't justify this - if you can you should believe this answer much more).
'i'+'mate'='imate'
'imate' enclosing 'n' is 'INMATE'.
'possibly' is the link.
Can you help me to learn more?
(Other definitions for inmate that I've seen before include "Occupant" , "Inhabitant of prison or hospital" , "One is in jail" , "One living in institution" , "Cell resident" .)