A war-like call to all nearby friends alerting them that you are in/ about to be in a fight.
TJ walks into a party, bumps into Pat. Pat starts to engage a fight with person A. Jessie who is upstairs and who is also TJ's best friend hears TJ yell, " YERP!," so Jessie runs down the stairs and attacks Pat.
by TJ De Franco August 24, 2010
A word common used in the ghetto's of Newark, NJ to initiate a public drug sale from a local thug. Usually associated with cocaine, crack rocks, heroine, or marijuana.
After I yerped at the gangster on the street corner, he then approached my car and proceeded to discuss a price for the eyeball of cocaine I was looking to purchase.
by Jason (elek) June 20, 2006