Ninja dick

When a guy sends a pic or video of his penis without warning. it comes out of nowhere like a ninja

I was messaging jack about the school work, then all of a sudden out of nowhere he sent ninja dick.

by humansvs aliens January 1, 2017

Ninja Dick

When somebody as an above average or otherwise huge penis when erect but shrinks to near disappearance when flaccid, or in other words vanishes like a ninja.

Example: That mother fucker has a ninja dick.
Example 2: I got ninja dick. that shit maybe 1 or 2 inches long till I get a hard on but then that shit massive.

by Pickle Reeves May 4, 2023

Ninja Dick

An uncircumcised penis.

Ashley : Brady has a total ninja dick, it was so weird!
Amanda : Oh gross no way!!!

by TheGingeyy November 4, 2017