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.

by KeriBlog March 20, 2012

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".

by Wobberino September 22, 2005

Jacknifing

When a hammock is set up taller than it is wide.

Wow, that person is jacknifing in their hammock like no one's business.

I mean, I've seen people jacknifing at a 90 degree angle before, but that person is jacknifing at an impressive 20 degrees.

by katgumball May 24, 2016

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.

by slappy bags February 5, 2010

Jacknifing

when you bend a dog in half and stick your knob in its mouth while someone else does it in the poopchute with a strap on. This way you and the other person can rub rusty sherrifs badges.

I jacknifed my collie last night. I think he might of liked it.

by dangerous dave April 13, 2005