Another variation of the common phrase "Dickhead" but a little more offensive to a Philly native... commonly used in Northeast Philadelphia, and Bucks County...
"Hey you know that boulJoey?"
"Yeah I know that boul, he a whole dickhead"
"Nawl dawg, he a SLICKHEAD ass nigga"
Stealing something quickly, quietly, and smoothly. Using a figurative "slim" or quick, nimble act of dexterity to scoresomething you want, often illegitimately.
"Damn, I just watched that kid slimhand a copy of God of War III off the store shelf right there."