An insult given to another person in an argument. It is commonly used on a person who has talked smack and or is being a smart ass.
Both sides can give the stacks, which will escalate to a bigger argument. However, it is not uncommon for one person to be the only one throwing the stacks.
Matt: Damn, man! Does your mother still dress you in the morning?
Avery: Woah! You're about to catch one. I'm about to give you the stacks.
Your forehead looks like a fucking Honda windshield.
Matt: Alright man, Chill. Chill.