When posting on a forum, you submit a post only to find that someone has posted the same thing only seconds earlier.
by mrespman November 04, 2005

v. the act of stealing, swooping, or snaking something. the person who has been ninja'd upon does not realize it for a little while.
Hey Marks and Giuseppe... you know Erin and Kek totally just ninja'd their way infront of you in line...
by badguy13579 December 02, 2007

1). Quick, stealthy appearance or escape.
2). Sneak attack from behind. In video games, often with a knife.
2). Sneak attack from behind. In video games, often with a knife.
I was on de_dust2 and he was the last guy left, so I went the other way, pulled out my knife and ninja'd him right in the back.
by Liquidnumb October 10, 2005

by nickers May 22, 2005

When someone takes something or someone away from you and you did not know whats the fuck is going on until the person ninja'ding you is laughing his/her/ ass off. The term ninja'd is usually mixed up with thiefed but the stupid sob that did that is spread across the atlantic ocean....Right now.
Tommy: Hey broski wheres my pencil....and my pants?
Charlie: Holy crap man those were ninja'd off you about a good 3 hours ago!
tommy: awwwwww mannnn!
(cue laugh track)
Charlie: Holy crap man those were ninja'd off you about a good 3 hours ago!
tommy: awwwwww mannnn!
(cue laugh track)
by Pruney The Transvestite January 17, 2010

In chat, it is the act of saying something before someone else. It only counts if someone else actually says the same thing afterwards.
by CraziAsian.... The one and onl February 08, 2010

(V): When someone gives another person such a good comeback that the person being exposed to the torment never even sees it coming. But the burn does not end there my amigos. The Ninja'er comes back for a second attack, ending with their battle cry, "Ninja'd!" Then disappears before you even have time to pee your pants from shock. Here's a diaper baby, clean yo'self up. You be dirtying up my new kitchen floors. .. bitch.
Person A: "I think I was just Ninja'd and I may or may not have just pee'd a little bit."
Person B: "Ninja'd!" *Disappears*
Person B: "Ninja'd!" *Disappears*
by Captain Elbow October 01, 2010
