Ninja Out 

To sneak out of place without anyone knowing.

To leave a place early without saying bye to anyone to avoid them making you stay

I don't want to drink anymore so I'm going to ninja out before anyone notices.

Danny always tries to ninja out early because he cannot hang.

Ninja Out by LW0WW May 25, 2011

ninja bomb

v. To leave a party without telling anyone you're leaving, so as to disappear- like a ninja.

Dirk dropped a ninja bomb last night, and no one heard peep from him for a week.

ninja bomb by 'noda March 10, 2007

[Ninja] Seed 

That marijuana seed that makes its way into your bowl/bong even after you're positive that you've meticulously sifted through and sorted all that bullshit out.

What's that taste? A ninja seed!

[Ninja] Seed by Emdoubleyou February 7, 2009

Ninja Swag 

FiercelyAaron's term for someone with immense swag. Ninja Swag is the highest of swag you can obtain.

I serenaded her with my ninja swag.

Ninja Swag by fiercelyaaron August 5, 2011

Ninja pipe 

The unseen blowjob

' I gave my man some ninja pipe whilst he was studying

Ninja pipe by Rinkax January 5, 2018

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