Top Definition
A person, usually male aged 13-35, who practices inferior self-taught fighting, killing, or stealth techniques in the basement of his/her parents' home or in a basement apartment. Typical hobbies include collection of decorative 'ninja' weapons for the purposes of practice and display. Typical behaviours include exhibition of martial arts proficiency, provision of stealth tips, and demonstration of human pressure points.
"Anybody who carries nunchucks to a 7-11 is a basement ninja."
by King Byron July 25, 2008

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A person(usually a teenager) who rarely sees the light of day and spends his time playing videogames ranging from: Modern Warfare 2 to World of Warcraft.
Me: Dude, I was enjoying a casual game of Modern Warfare 2 when this 10th Prestige dropped into my game and fucked everyone up.
Friend: What a fuckin Basement Ninja.
by KillerKore13 December 12, 2009

The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Your favorite word on a white mug.

Create a mug

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug

The Urban Dictionary T-Shirt

Soft and offensive. Just like you.

Buy the t-shirt

The Urban Dictionary T-Shirt

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

Buy the t-shirt