(archaic, thieves' cant) The leader of a group of thieves.
Esimerkit
And the anger of the LORD was kindled against Moses, and he said, is not Aaron the Levite thy brother? I know that he can speak well.
- - - the Junior Prom with boys whose names are right out of the grade-school reader, not Aaron and Arnold and Marvin, but Johnny and Billy and Jimmy and Tod. Not Portnoy or Pincus, but Smith and Jones and Brown!