To not participate in dysfunctional and/or unhealthy behavior. Often, such behavior is commonplace in one's family, and the person breaking the cycle does so to keep it from continuing through future generations. I don't drink at all because I come from a long line of alcoholics, and I am determined to break the cycle! You need to break the cycle of procrastination, Michael. It is seriously starting to affect your grades.

slang A motorcycle, referring to the likelihood that a motorcycle accident will result in the rider becoming an organ donor due to fatal injuries. You know Mom thinks of motorcycles as donorcycles. She'll freak out if she sees you on one!