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33.
Adjective

A descriptive word for something that is not good.

Synonyms could be: Lame, boring, stupid.

Particularly refers to scenarios.

This word may derive from jail or prison slang.

The word probably derives from the onomotopeia of 'quack'.

Utilizing the actual word:

You are at a party with a bunch of ugly-ass chicks and they're serving cheap beer. You also had to pay to get in. And some drunk idiot keeps switching songs on the player right in the middle of them.

"Hey man, let's get the fuck outa' here. This place is quack!"

-OR-

Utilizing the actual sound:

You are at the above party, and the ugly chicks are talking to you and your friend but you don't want to offend them (you might drink and dial later). So, you look at your friend, and instead of doing that slight raising the eyebrows nod-thing, you just make the sound "quack", or "eerack, erack" using a twisted-lip, things-are-lame look while possibly rolling your eyes.
by BunnyBrown May 24, 2008
 
1.
A doctor of questionable ablitiy and reputation.
Even tho Erin's dad claims to be a doctor, I say he's a quack! He didn't even graduate high school!
by Stella Lafayette December 04, 2004
 
2.
The sound a duck makes
"Quack"
by Lindsay February 25, 2003
 
3.

1. a fraudulent physician

2. any physician
This quack has no skills in medicine at all.
by Light Joker December 31, 2005
 
4.
A very sexy sound when moaned by a girl.
guy: so what do ducks say?
girl: ...quack.....
by MallardDuck January 31, 2009
 
5.
A scam-artist. A person who makes up bullshit medical products or advice or prescriptions that don't work. A snake oil salesman.
Most alternative medicine "specialists" and psychics are quacks.
by Anonymous February 17, 2003
 
6.
noun: slang for "crazy" common in the south, especially near areas of high duck concentration.

1. That's quack, man.

2. You're so quack.

3. Dude! that's quack, yo!
by thats whack February 22, 2009
 
7.
-To quack is to perform an act that displays one's stupidity, incoherence, lack of coordination, or outright inability to relate or adapt in a social setting. Derived from the sound a duck makes, more specifically the verb form for what a duck (see definitions 5,8, and 9 for "duck") does.
-To fuck up the situation for everybody.
You missed the biggest quack!
What happened?
____ ran down the hill, tripped and busted ass all over the sidewalk and fence by the tennis courts!

How was your birthday?
Fun as shit, we got fucked up then ______ quacked ridiculously by hitting the blunt BACKWARDS! He didn't even notice for like 2 seconds, then he got up and slid down the hill and lost his keys.
What a fuckin' quack

I dropped the entire pizza on the ground.
You're so quackin.
by DaQuackyPaki December 06, 2009