Petty gangster (7)
I believe the answer is:
hoodlum
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">petty gangster</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for hoodlum that I've seen before include "Petty gangster" , "Aggressive young criminal" , "Young thug or gangster" , "American thug" , "Small-time gangster" .)