"Jump/ing on da rocks" means,
A. To start the act of drinking, or to work towards getting "crunk".
B. Means to actually jump on rocks, in a form of quick fluid movements over and up rock and/or rocky areas such as hillsides or rocky rivers.
C.When a female is attracted to a male(you), in this case "da" is substituted with "my". This is a less often used form, the common form would be "balls" instead of "rocks".
Yo man tonight i gotta jump on the rocks, because i really wanna get drunk.
1. A positive comment that something is good or pleasing to the eye.
2. A negative comment meaning that someone is insane, like a rabid dog off the chain.
Examples:
1. Girl, those braids are off da chain. Where did you get that weave from?
2. Your mommma is off the chain and chasing that poor fool down the street.