1. vulgar slang A penis, especially when erect and inside one's pants (as if it were in one's pocket). I didn't want to stand up and make it obvious that I was sporting a pocket rocket.

2. slang A miniature electric or gas-powered motorcycle, as might be ridden by a child. David's dad bought him a pocket rocket for his birthday—the thing looks like real deal!

3. slang A compact vibrator specifically used for clitoral stimulation. I was mortified when my pocket rocket fell out of purse halfway through the date.