Nothing, or something equivalent to nothing. Jack shit has the remarkable property that its absence and presence are identical. Typically used with or without a negative to describe a total lack of knowledge, value, or significance. Its use carries a strong negative connotation which can express frustration, disdain, ignorance, or other negative qualities.
I don't know jack shit about that. / I know jack shit about that.
It's worth jack shit. / It isn't worth jack shit.
I didn't get jack shit. / I got jack shit.
by cazort June 1, 2005
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A term used to describe a lack of anything.
I ain't got jack shit to do. You don't have jack shit. I don't owe you jack shit!
by Carter SN October 1, 2005
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1) A term most commonly used for when people describe that they don't know, or have not done anything.

2) Probably the name of some guy somewhere, who i'd -really- like to meet.
Bob: "Bill, what do you know about egg products?"

Bill: "Heh, Jack shit, Bob."
by Meik April 2, 2003
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1. To have nothing.

2. In texas holdem hole cards consisting of jack two of anything.
Ie: I have jack shit for money.

I had to fold when I caught jack shit.
by phoenix 1997 July 11, 2010
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1. jack rabbit feces.

2. something plentiful and omnipresent, yet nonetheless worthless.

3. nothing, or nothingness
(see jack squat)
"This here jack shit ain't worth jack shit."

Incorrect: "He don't know jack shit."
Correct: "He knows jack shit."
by Joe Bone March 11, 2005
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when you are taking a shit and getting a handjob at the same time
what'd you do last night?
Jack shit....
Oh that must've sucked...
No... no sucking... just a handjob
by jackshit March 4, 2008
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