Someone who will stop you as you walk and tell you:
a) You look good, son. Naw, naw don't leave, I jus wanna talk ta ya...
b) I will take verbal abuse for change
among many other statements. They will often smoke weed or crack right on the street, and the cops don't care. They have an 'ignore the bums' policy.
These bums will often wander onto campus to have enlightening conversations about the bible, only to pass out in the middle of a pathway.
They are generally nice people, some even have advanced degrees, but somewhere along the line (around 1967-1975) they just fucked up and couldn't recover. Most of the sleep in people's park.
Paco: Yo G, you see that Berkeley bum?
Jaime: Yeah, how'd he get all the way down to Stockton?
Paco: Shit if I know, but he taught me about the space-time continuum, I feel like I might go back to school.
Jaime: Yeah, they are pretty smart, but yet they don't do shit with their lives 'cept create elaborate radio mixing equipment next to Top Dog.