To occaisonally or recreationally use heroin without becoming trully addicted.
I've been chipping for years, but I'm lucky I've never got hooked and had to experience withdrawl symptoms.
The state of being in active withdrawal from heroin or other opiates. "Kickin" comes from the involuntary leg spasms that occur when your withdrawing from heroin.
"I havn't fixed for two days and I'm kickin real bad."