Jackknife

A knife that folds out of the handle!

You know you’re dead when that jackknife folds!

Me: *sees jackknife*
Stabber: *folds knife out of handle discreetly*
Me: *runs away*

by Stabberman420 March 31, 2020

jackknife

When you jump off of something and the front of your foot lands on something but not the back, causing your foot to be shoved upward as you leg goes down

“I just jackknifed my foot on the stairs, my Achilles tendon is torn”

by Onlygirls5'10andabove January 28, 2024

Jackknife

The action of pulling your pants down while driving, squatting above the seat, reaching your hand underneath your bottom, defecating into your hand, and then using the feces to smear your windshield. Done ritualistically for courting purposes.

The man decided to jackknife while driving on highway 99, in an attempt to enamor his lady friend.

There are people who jackknife to relieve stress during bumper-to-bumper traffic.

by English Professor with a PhD December 8, 2017

New Jersey Jackknife

When someone loses control of their car and bounces from wall to wall and back across to the other wall again.

Did you just see that Civic do the New Jersey Jackknife across the turnpike?

by LongIslandTom March 8, 2021