Illegal ticket seller (4)
I believe the answer is:
tout
'illegal ticket seller' is the definition.
(as in a ticket tout)
This is the entire clue.
(Other definitions for tout that I've seen before include "Try to sell in a direct manner" , "Profiting ticket seller" , "Seek business in a direct manner" , "Solicit custom brazenly" , "Peddle; ticket seller" .)