n. a moron; one who "jacks nuts" or beats off.
Hey, jacknut you missed the fucking turn back there.
by danielle November 30, 2003
A jacknut is a less offensive term used to insult someone.
Derek, you're such a crazy jacknut!
by Harry Johnson April 28, 2003
Someone, or something that is not worth a Fuck.
My new Supervisor is a Jack Nut.
by Carlito's Buey January 07, 2011
a insult usally directed towards a pricish person. Possibly made up while rambling anger towards a person.
God dammit! Ur such a fucking jack nut!
by PoniesArntUs April 07, 2009
when a gentleman has very small testicles (or possibly humongously large ones)
check out the jack nuts on him, he looks like brad micklea!
by biz markee August 21, 2003
(v) To attack, either verbally or physically, someone who should be considered sympathetic or friendly to the attacking party.
Dude, Fox News totally jacknutted Ron Paul.
by Rock79 August 15, 2011
A game, invented by me, for couples to play while driving together. It is a simple game, somewhat like slugbug or punchbuggy, but has a fun twist. When they are on the road, they will notice some drivers doing stupid, dangerous, and illegal things (these people are called Jacknuts). When they see these rediculous acts of traffic moronism, they must try to identify whether the Jacknut in question is male or female. If able to determine this, then the game proceeds as follows: When the Jacknut is a male, the woman gets to punch the man. When the Jacknut is a female, the man gets to punch the woman. Don't forget to say "Jacknut" when you punch your significant other (only in the arm, of course). That is Jacknut. It is a simple yet entertaining game which you will never grow tired of playing and since the world is full of horrible drivers, you will have an endless supply of Jacknuts. Spread the word about Jacknut and get out into traffic and start playing!
This was a boring drive until we started playing Jacknut!
by jacknut January 08, 2012