(1)this word replaces boy, man, dude, etc;
(2)opposite of "ol' head" (another common Philly word)
-mostly used with the word young
Fall back shorty, I seen you f***in' wit' bul last week.
sup bul? Where you been at?
As a remark:
damn bul! That ain't cool.
As a meeting word:
Yo bul. What's going on?