Where a man gets pleasure on his dick from using his own two hands
George: Rob, guess what I just saw!?
Rob: what George?
George: I saw Billy jacking off. No girls were around at all!
Can be used as a noun to refer to a guy who wastes time, is a complete loser, and cannot get anything done. This guy may well be popular with friends, the ladies, and whomever he meets, but has never accomplished anything and never will. Anything he has tried to achieve has ended up in disaster.
That Kramer on Seinfeld sure is funny even if he is a complete jack off.
Steve, did you complete the final report so you can graduate from high school next week?
No. I'm such a complete jack off that I never get anything done.
Smoking pot will really just turn you into a lazy jack off.
jack off is what most young guys often like to do.
I was twelve when my older cousin taught me how to jack off -- I couldn't cum, but it felt awesome -- and when I squirted my first load, it was unbelievably awesome!
When a male masturbates while thinking of Jack Bauer; the worlds only alpha male
I was caught jacking off by my mother
When a man who looks like their name is Jack. Just goes off on someone when they are really mad. And puts their hand into a fist and starts shaking it with rage.
Bro I think Jack is about to start Jacking Off.