Describes a mate or partner that has perfected his craft through years of seeming like a great catch when in all actuality...he suddenly, and stealthily reveals himself as a complete douche bag.
Great husband and family man...and poof, the douche ninja comes out of nowhere and reveals that he is a cheating, lying scumbag. You had no idea. Surprise attack. Many victims.
by Sonny James August 29, 2013
Person 1 " so hows life"
Person 2 " its a secret"
Person 1 " you can tell me your secret"
Person 2" its a ninja secret"
Person 1 " what?!"
Person 2 " I dont even know the secret, there for its a ninja secret"
Person 2 " its a secret"
Person 1 " you can tell me your secret"
Person 2" its a ninja secret"
Person 1 " what?!"
Person 2 " I dont even know the secret, there for its a ninja secret"
by secretkeeper524 January 19, 2012
A person who lacks the common sense to avoid antagonizing ninjas. A social klutz who does not know how to behave in public. Missing hands or fingers is a sure sign, but not required.
I can't believe that you just ate my BK mini burger off my plate, you are such a ninja petter!
You: Let's wait for the light to turn before we cross.
Me: You are such a ninja petter, there's no traffic.
You: Let's wait for the light to turn before we cross.
Me: You are such a ninja petter, there's no traffic.
by bravo delta August 16, 2011
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
by sparklinwiggler August 30, 2008
when you pretend to be hard at work to get your mom off your back about homework, but you're really watching tv shows on hulu.
I was ninja studying last night. Learned everything off of bones and house. Think I'm ready for that biology test now!
by you can't see me! February 12, 2010
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