Ninja-Signing

When an author secretly signs his/her own books in a bookstore without the bookstore's knowledge.

Brandon Sanderson is ninja-signing books in airports.

by jackatthekilns November 10, 2009

Ninja bounce

To leave a room of people without saying goodbye. To leave unnoticed, like a ninja.

I was so tired at the party last night, I totally ninja bounced.

by WordsImakeup33 September 4, 2015

Ninja Brian

the only ninja as far as I know in the band NinjaSexParty

Goddamn Ninja Brian you killed em all

by darkclaw wolfgod February 20, 2022

ninjas on the roof

impending doom

as soon as i walked in on Stacy and Jill and that 6 foot toedo, i knew there were ninjas on the roof! Phil would be pissed.

by freewilly23 January 18, 2009

Ninja Ad

An advertisement that appears out of nowhere, usually containing some sort of virus and/or clickbait.

"Aw shit, I was watching porn last night and a fucking ninja ad came up and I accidentally clicked it, and now my computer's got a virus."

by Tumbleflop April 19, 2018

Ninja's Ligma

Its when you watch his stream once. It kills you slowly. One tried to get people to do the floss and nobody cared and done it.

Yo man, why would you watch Ninja? Now you have Ninja's Ligma it was nice knowing you man.

by Dashie tribe May 8, 2019

ninja swipe

to discretely (like a ninja) tuck an erection under the waistband of underwear or belt line of pants.

a true ninja swipe is done in one swift motion.

yo, i was freeballing in my sweats when i got a boner- i had to ninja swipe that shit so it wouldn't look like i was proppin a tent

by princealberto July 7, 2009