The act of jerking off (typically a man), especially to the point of orgasm.
Originates from the term "jacking off" as well as the similarity of the "cracking" sound from performing it and the opening of usually alcoholic beverage bottles.
It is also a popular perversion of "cracker jack", the brand of caramel corn.
Roommate: "You two were so loud last night! I heard you cracking jack so loud I couldn't get to sleep!"
"Yo, she was cracking jack so hard i almost passed out!"
When somebody is pissing you off
Random guy: your kinda gay. Me: your really jacking my squash right about now
your not getting it back it’s took/stolen
Anna asked for her money back but imma bunk jack
A person who will stalk another person via social media and drive distances up to 1,000 miles to stalk the person at their workplace and home.
Do not talk to Susie because became a Jack-Stalker after billy broke up with her.
The appearance of a highly sexually active older woman`s vagina. A hanging and leathery labia, resembling the flappy bits at the top a pirate`s boot.
"Steve, I saw you getting off with that blonde MILF last night. What was she like, then?"
"Bud, she went like a fucking steam train. Her twat was a bit worn out though; pissflaps looked like the top of Jack Sparrow`s boot".