Top definition
1.(noun): Zachary "Zack" Morris, the main character from "Saved by the Bell"

2.(verb): The act of doing something very outlandish and/or surprising that brings great joy to many people. (It can only be done by someone named Zack, Zach, Zak, etc.)

3.(noun): A nickname given to any "Zack" who is viewed as spontaneous or unpredictable by his peers.
Zach Attack: Hey, Mr. Belding. What brings you to study hall?
Mr. Richard Belding: Don't get cocky, Morris. I've got my eye on you.
Zach Attack: Sorry, sir... You're not my type.

Guy #1: This party sucks, they're already out of beer!
Guy #2: Are you kidding!? Wow, let's get out of here...
(Zack enters with a keg, a 30pack of Bud, and a funnel)

Girl #1: Hey, have you seen Zach anywhere? He promised me we'd dance tonight!
Guy: Oh, Zach Attack? Yeah, he's either in the living room playing pong or outside jousting on that Big Wheel he bought on eBay last week.
(Girl #2 enters laughing hysterically)
Girl #2: Everybody come quick! Zach Attack's on the roof throwing Jawbreakers at the Trick or Treaters!
by The TampaBay Tyrant March 25, 2009
Happy St. Patties Day!
(V) Though the name suggests violence, it is an action of truth and love inspired only by people as groovy as Zach's. The process of screaming to, jumping out at, and randomly hugging a Zach.
(Friend of Zach): *sees Zach* ZACH ATTACK!!!!!!!! *jump and hug*
by katiegee7777789 November 21, 2010
Happy St. Patties Day!
when 3 or more people with the name zach (zack) walk around in a group
dude did you see that zachattack walking around school today?
by Conrad5220 November 22, 2011
Happy St. Patties Day!