Prohibition restricting member, one working in pub (6)
I believe the answer is:
barman
'one working in pub' is the definition.
(a barman works in a pub)
'prohibition restricting member' is the wordplay.
'prohibition' becomes 'ban' (ban is a kind of prohibition).
'restricting' indicates putting letters inside.
'member' becomes 'arm' (member can mean a limb).
'ban' going around 'arm' is 'BARMAN'.
(Other definitions for barman that I've seen before include "Drinks dispenser?" , "Pub employee" , "He works in a pub" , "Drinks server" , "One employed to serve" .)