Top definition
Children that are under 50 lbs and taking any type of martial arts class.

Damn, do you see all of those car-seat ninjas outside of the dojo yesterday evening?, Cosmo Kramer pwnd a bunch of car-seat ninjas.
by Byrd-Man April 12, 2009
Get the mug
Get a car-seat ninja mug for your coworker Yasemin.