We don't have synonyms for bag man yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are bagman, big man and bad man.
(n) :
Alternative form of bagman. [(US, Australia, New Zealand, informal) A person who collects, transports, or distributes illicit money, especially for the purpose of bribery, extortion, or the making of other improper payments.]
(n) :
Alternative form of bagman. [(US, Australia, New Zealand, informal) A person who collects, transports, or distributes illicit money, especially for the purpose of bribery, extortion, or the making of other improper payments.]