Pole briefly working for builder (5)
I believe the answer is:
mason
'builder' is the definition.
(thesaurus)
'pole briefly working for' is the wordplay.
'pole' becomes 'mast' (mast is a kind of pole).
'briefly' means to remove the last letter.
'working for' becomes 'on' (I can't justify this - if you can you should believe this answer much more).
'mast' with its final letter removed is 'mas'.
'mas'+'on'='MASON'
Can you help me to learn more?
(Other definitions for mason that I've seen before include "secretive lodger!" , "He works with stone - may be free" , "Builder in stone" , "Secret society member" , "A worker in stone - may be free" .)