The sound uttered to signify that someone just got scammed or publically shamed.
A guy fails at picking up a girl and walks back to his friends. He is met with a chorus of "Quaaack."
or
"That sucker got seriously quacked by the salesman at GoodGuys. Buyer Protection Program? Quack!"
One might use the word quack, at high school, to alarm friends that a teacher is approaching and they should stop doing whatever it os they're doing wrong.
If a friend is smoking or on their phone, say 'Quack,' to casually tell them a teacher is approaching.
What somebody claiming to be spreading magic is known as.
The quack claimed to be spreading magic like wildfire or a virus.
If someone tells somebody wearing a seatbelt isn't using enough caution, common sense, or good judgment, that they need to have on a motorcycle helmet and biochemical suit, and a bunch of other things not required for a trip to the grocery store, wouldn't their definition of common sense be as questionable as everyone else's? And if it would, wouldn't the same thing apply to wearing masks, getting vaccines, and doing everything else they are told to do before they can resume their lives?
Resuming life, unpausing life, might require a little standing or even fighting. Otherwise, people are going to keep getting told when they can resume life by the same people telling them what they have to do next to do so. A lot of livelihoods have already been lost as businesses closed, those livelihoods aren't guaranteed to come back some day without a fight. A doctor that can't be questioned about whether or not they are a quack is like a religious leader that can't be questioned about whether or not they are a charlatan. There is no one person alive, male or female, that isn't questionable.
When a girl likes you and gets nervous around you so she has no other reaction
Katie: Oh look it’s John, quick what do I do
Friend: idk shoot your shot
Katie: quack
John: wtf