|1.||Middle Finger Swear|
Used as an oath to convince someone that you will do something, not do something, say something, etc.
It's like a Pinky Swear except stronger.
Also called MF Swear.
"dude if you slap that girl's ass I'll pay you 5 bucks>"
"ok, Middle Finger Swear on it."
"ha ha newb now you have to pay, we MF Swore on it"