Quack 

To masturbate, male or female

So my girlfriend is on her period this week, and ive had to settle with quacking off.

Quack by Same Cup Ward August 15, 2008

Quack 

The strangely annoying squawking sounds that most ducks make.

The duck quacked madly at the flying hamburgers.

Quack by Mongooose August 2, 2009

Quack 

in very complicated chipmunk terminology this sound is often referred to as "sex" or even "fuck" in the mating season (12 Months a year).

"Damn woman you look fineee! we should Quack!"

"Why yes, a quick Quack is what i need right now."

Quack by chipmonk182 September 5, 2011

quack 

An online or e-slut who will often prey and stalk pre-pubescent teen boys via the internet.

Quack and nightfall cyber while playing WoW.

quack by Tom Bolton November 4, 2006

quack 

A pseudomedical "professional" who earnestly believes in their products or procedures (as opposed to a fraud, who knows he is full of shit and just wants to make money), which in actuality are of dubious merit and are possibly injurious.

(Name) the quack (my chiropractor)
Was a squat little ape
With a mouse's voice
And a pigeon's gait

quack by Anon343 March 16, 2008

Quack 

alternative term for the act of passing wind, but done so with tremendous gusto!

Franny has let out a horrific quack.

Quack by Wayne August 20, 2003

quack 

To claim possession of something for when you return, such as a seat. Short hand for the phrase "quack quack I get my seat back"

Counter arguments include:
1. Move your feet, lose your seat
2. Cluck, cluck, I don't give a fuck!

Abby gets up from the couch and says, "Quack!"
Abby has 'quacked' her seat, thus no one else can take it.

quack by Savannah Cheyenne February 18, 2008