Jain is an act of Ninjaing, or stealing an item or thing. It can also be used as a noun in which the person calls someone a jain. This meens that this person is a person who ninjas or steals things, or that person is really really gay. Also one can yell jain to imply they are angry or simply to be inine.
Nick says "aaron you jain, you just stole my dignity"
Medivh says "Wow you are a complete jain" Instead of saying "Wow I completley hate you your gay.
Aaron yells "JAINNNNN"