A team scores and some dude says "high five man!" then as you are giving the high five turn your hand around to give the "back five." Maybe because you want to be cool with that person (not leave them hanging) but you're just not into it - it's like a weak high-five or a half-high-five.

phone: why don’t you go to sleep tommy it’s 2 in the morning?
tommy:why don’t you die you dumbazz

The pimp raised his hand to the hooker and proceeded to back-five her across her face till she was able to pay him the allotted amount of cash.

The back of the pimps hand was sore from giving out so many back-fives.

What's better than a high five?? Back five...Invented circa 1981 by the one and only "mike nyce"

It's not my fault I slapped Joe, he has a backfive.

Hey bro back five! “Knuckle on knuckle connect”