Trade stoppage thus limits a degree of business (7)
I believe the answer is:
embargo
'trade stoppage' is the definition.
(synonyms)
'thus limits a degree of business' is the wordplay.
'thus' becomes 'ergo' (I've seen this before).
'limits' is an insertion indicator (limit can mean to contain or block off).
'a degree of business' becomes 'MBA' (Master of Business Administration degree).
'ergo' placed around 'mba' is 'EMBARGO'.
(Other definitions for embargo that I've seen before include "Trade stoppage" , "Trading ban" , "Official ban on trade or commerce" , "Commercial break" , "restrict trade" .)