Prevent fellow from becoming a publican (6)
I believe the answer is:
barman
'publican' is the definition.
(thesaurus)
'prevent fellow' is the wordplay.
'prevent' becomes 'bar' (bar can mean to prevent or disallow).
'fellow' becomes 'man' (fellow can mean a man).
'bar'+'man'='BARMAN'
'from becoming a' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for barman that I've seen before include "Drinks dispenser?" , "Drinks server" , "Club worker" , "In pub he might pull" , "He works in a pub" .)