Jacknife 

When you burst out laughing, so hard and so suddenly, you involuntarily fold in half at the waist. Usually accomponied by a large exhale of breath.

It was hilarious, and when he hit the punch line, I jacknifed.

Jacknife by KeriBlog August 2, 2012

jacknife 

a bad ass close to the same qualities of Jesse James and D.B. Cooper. Also has an extremely huge dick and is amazing in bed.

damn, that guy nicknamed jacknife kicks my ass!

yeah i know, he banged my girlfriend then dumped me cause apparently he fucks her better.

jacknife by slappy bags February 4, 2010

Jacknine 

A jackass who's acting assninel

He was being sarcastic and rude he's Jacknine

Jacknine by Ljetwh75 May 2, 2018

jackknife

From what I know, it's when an 18-wheeler is carrying one of those loads, any loads, as long as it's carry a load, and it's going at quite a highspeed, suddenly braking, causing the actual truck itself to brake whilst the load's momentum behind the truck forces itself in motion against the truck, causing the load on the back to be intersecting at a perpendicular angle with the truck. Look at this---> |_ The | is the actual truck and the _ is it's load. The truck (|) is going forward, whilst the load (_) is scraping it's tires horizontally.

A jackknife is also responsible for causing many highway accidents, because when a truck jackknifes, it takes up all the lanes on the highways, and leaves no mercy for the vehicles in its path! Always speed up if you see a jackknife coming toward you if you cannot rapidly get off the highway.

*people driving*
Oh crap dude, that truck is in the process of a jackknife, that piece of shit volkswagon is in our way, guess the only choice we have is to speed up, step on it.
*person in volkswagon*
*ahhhh this is the life, *fart*, beer and hot sauce...boomheadshot.*

jackknife by Cobain will have justice. November 28, 2005

jackknifed 

v. tr.

1. Referring to automobile accidents, when a car is totalled to the point of folding in on itself, much like a jacknife.

Holy shit, Zach's new car got jackknifed by a pickup truck! What a tard!

jackknifed by SabDek April 19, 2003

Toledo Jackknife 

When a male attmepts to fellate himself however the extreme angles involved cause him to throw his back out, and he is stuck in that position until help can arrive.

Hey, Steve got caught in a Toledo Jackknife, again.

Toledo Jackknife by Benevir August 23, 2007

Jacknifing 

When a man has an orgasm while his penis is semi-erect.

"Man, I was so sexed-up last night - I started jacknifing the second she put her lips on my cock".

Jacknifing by Wobberino September 28, 2005