ninja hamster 

Any of a subfamily (Cricetinae) of small Old World rodents trained in ancient Japanese martial arts and employed especially for espionage and assassinations while having very large cheek pouches.

Holy crap! My cat just got jumped by a ninja hamster!

ninja hamster by Anonymous November 2, 2003

ninja bump 

When someone on an Internet Forum replys to a post, and then quickly deletes their post, so the post appears at the top of the list mysteriously

ninja bump!

ninja bump by FlinxSL April 19, 2004

white ninja 

The act of disappearing home from a night out without saying goodbye, usually at a nightclub.

I got back from the bar and my best mate was gone, He must have done a white ninja.

white ninja by The Jesticles January 21, 2010

ninja'd 

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

Ha ha, Julia Roberts is so lame.
----
Ha! Julia Roberts is so lame.

EDIT: DAMMIT! Ninja'd!

ninja'd by mrespman November 4, 2005

Ninja plz 

a term used to replace "nigga please" so if you say it to someone they cant get mad at you for a racial slur.

Mike: Yo man you wanna bite of this turkey sammich?
John:Ninja plz! I aint need no taste of yo grubby lil sammy!
Mike:Hey dont call me a nig...oh wait nevermind.

Ninja plz by maxatron January 7, 2009

Ninja Wank 

the art of wanking quietly and discretely in public or in an area of high visablity, or simply the art of wanking like a ninja.
A secretive faction of monks from long and far have mastered this form of masturbation whilst going out there daily rituals.
It is said to bring inner peace and balance to ones self, but costs a fortune in laundry bills.

only the masterful eye can see someone having a ninja wank, but if someone does this would be the reaction...

man 1- 'Dude wtf is that man doing in his pocket?'

man 2- 'Must be having a ninja wank'

man 1- 'Holy shit i thought that was just in fairytales'

Ninja Wank by Shaggy Quinton June 24, 2010

Ninja Deuce 

When you take a particularly nasty shit in the bathroom of someone you hardly know, then tell no one, like a true ninja master.

Holy shit dude, I am pretty sure that Rachel's friend whatsherface, ninja deuced us last night. Thats the last time i have her friends over for Mexican food, twat.

Ninja Deuce by Arsenal89 August 15, 2008