"The point directly above, below, or at which a nuclear explosion occurs" (Merriam-Webster). Recently thanks to a load of rhetoric from our idiot newscasters, the meaning has been horribly trivialized.

Hiroshima (80,000 deaths from the explosion + additional 60,000 deaths from radiation poisoning) is a "ground zero". Nagasaki (120,000 deaths total) is a "ground zero". The World Trade Center (2749 deaths) is NOT a "ground zero". So stop calling it that.
IDIOT: My uncle visited ground zero.
SMART GUY: Really? Your uncle went to Japan?
IDIOT: wtf is a Japan?
by Brendie December 12, 2006
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The epicenter of a disaster or explosion.

Currently, the term is most commonly used in reference to the location of the World Trade Center after the September 11th attacks.
It took much less time than expected to clear the debris from ground zero.
by Meggo May 18, 2004
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where the dropping of one's bowels occurs. the height of the stink zone.
Dude, that is nasty!

Yeah bro, and you're just getting the second-hand smoke. It's 10 times worse at ground zero.
by jeremyf September 25, 2007
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A popular guess of Katsuki Kacchan Bakugou’s hero name.
Omg, is that Ground Zero?? Oh, he’s with the chivalrous Red Riot! #GroundRiot for life!
by FrenchBaguette101 October 08, 2018
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A state of being wherein you feel as if you cannot sink any lower emotionally, psychologically, or physically.

Hitting rock bottom.

The absolute lowest possible point or level. The place a person in denial must reach before he finally is ready to admit that he has a problem and reaches out for help

....but hey, when you cant get any lower, the only way to go is up.
She was emotionally at Ground Zero. Britney hits Ground Zero, just days after she lost physical custody of her two boys.
by Aimee Sheep November 21, 2007
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To reset a conversation, object or situation to it's original or prior form. Especially if the given situation is extremely undesirable.
I don't even know what we're talking about at the moment, let's ground zero this conversation right now
by lunchZA October 29, 2018
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