Ninjavitis most commonly occurs among those who wear wrestling shoes, women with small feet, and the Japanese.
Person 2: Dude, you scared the crap outta me! It's like you've got ninjavitis.
See also: sidler, sidle
2. When the physical state of ones mouth is so repugnant that it looks like a skilled ninja has drop-kicked them squarely in the mouth.
2. god rest his soul, but ODB musta been in a fight with the RZA cause even his goldfronts had sum ninjavitis
"I can't believe I got with that ugly bird last night, Ninjavitis strikes again"
"Mate where did everyone go last night? Oh Ninjavitis"