Having sex as quietly as possible because there are people who could possibly hear you if you went at it the usual way.
My parents are staying in the guest bedroom next to ours so tonight we will have to have Ninja Booty.
by GassyLittleElf April 20, 2007

When someone appears or disappears from the surrounding area with few or no people noticing.
Also when you do a really cool ninja move, especially if you could never do it again.
Also when you do a really cool ninja move, especially if you could never do it again.
Joe: Oh, hi Jon.
Jon: Hi Joe.
Sam: Hey guys!
Joe: When did you get here?
Jon: He pulled a ninja.
Man: *drops glass*
Waiter: *catches glass without spilling drink*
Man: Wow, you just pulled a ninja!
Jon: Hi Joe.
Sam: Hey guys!
Joe: When did you get here?
Jon: He pulled a ninja.
Man: *drops glass*
Waiter: *catches glass without spilling drink*
Man: Wow, you just pulled a ninja!
by StarGazer453 October 15, 2010

by sparklinwiggler October 19, 2008

A person who occupies a bathroom stall and refuses to make any BM noises until the entire bathroom has been vacated. Occasionally, a bathroom ninja will even go so far as to stand on the toilet seat to avoid detection by other bathroom-goers.
Jacob hid in the shadows cast by the stall walls like a bathroom ninja until the final shitter had left the restroom.
by timr211 August 15, 2014

–noun, plural -ja, -jas. a member of a modern society of mathematical agents, highly trained in stealth calculatons and number theory, who are hired for covert purposes ranging from solving the worlds problems to passing on their skills to the next generation.
by KSignell February 6, 2010

Societal ninja (noun): an issue that caused great discourse in society. The issue was once at the very forefront of mainstream media’s attention, causing fierce debate and social divide along community lines; racial, religious, political, ethnic, gender and/or age. The issue is often deeply rooted in history and culture. Suddenly, the issue is gone without a trace from mainstream media; the key is there must be no resolution or majority acceptable action reached. The issue falls from the forefront of media often because another story breaks, acting as a ninja’s smoke bomb, and media never returns to the issue until it reappears as a result of the offenders actions-no more CNN or FOX headlines.
Example:
Malcom: Whatever happened to the two guys who dressed up in blackface in Virginia? Who was it—the govenor and attorney general and are democrats too?
Martin: That’s a good question, Malcom, I haven’t heard anything about that situation lately. It was on CNN and Fox non-stop for weeks and now it just disappeared without a trace. I guess they resigned. I really thought we had overcome.
Malcom: As I always say, I’m for justice no matter who it’s for or against and societal Ninjas such as these prevent communities from ever realizing justice and sustainable positive change. These soNinjas raise their ugly heads for a moment and then hide in the dim unknown giving people the false impression that it’s resolved, but it’s not. No justice no peace as the young folk say! I highly doubt if those Kats resigned.
Example:
Those dudes committed a federal crime and never went to trial and after one day of headline reporting it’s gone-that is soNinja! I think they likely paid off the judge because I haven’t heard about this in ages.
Malcom: Whatever happened to the two guys who dressed up in blackface in Virginia? Who was it—the govenor and attorney general and are democrats too?
Martin: That’s a good question, Malcom, I haven’t heard anything about that situation lately. It was on CNN and Fox non-stop for weeks and now it just disappeared without a trace. I guess they resigned. I really thought we had overcome.
Malcom: As I always say, I’m for justice no matter who it’s for or against and societal Ninjas such as these prevent communities from ever realizing justice and sustainable positive change. These soNinjas raise their ugly heads for a moment and then hide in the dim unknown giving people the false impression that it’s resolved, but it’s not. No justice no peace as the young folk say! I highly doubt if those Kats resigned.
Example:
Those dudes committed a federal crime and never went to trial and after one day of headline reporting it’s gone-that is soNinja! I think they likely paid off the judge because I haven’t heard about this in ages.
by Ean M. Williamssom March 16, 2019

when you think you're going to sneeze, but then you don't. it's there one moment, and then it just disappears like a ninja!
Friend 1: *look of concentration*....dang!
Friend 2: what?
Friend 1: ninja sneeze
Friend 2: aw, i hate that
Friend 1: i know right?
Friend 2: what?
Friend 1: ninja sneeze
Friend 2: aw, i hate that
Friend 1: i know right?
by XxCottonCandyStarsxX May 18, 2009
