What's on your mug?

Halo; Exclamatory: Phrase uttered after sticking a plasma grenade to a foe. The quarry thus knows he is doomed.

I thought I'd won the firefight, but I got backpacked at the last second.

By Duke Greene

Slang for when a mans testicles slide in betweens his buttocks.

Bob: DUDE, the lifeguard looks like he's got no nuts! Dave: No, he's just got a backpack. Martin:FUCK I'VE JUST SAT ON MY TESTICLES AND NOW I HAVE A BACKPACK!

By outoftheblue22

a really attractive girl aged between 17 and 21.

"check out that delicious little backpack over there"

By King of Backpacks

In reference to someone who is ridiculously and outwardly stupid, as in jumping off a plane with a backpack instead of a parachute; absurd unintelligence.

I talked to that tool for more than an hour, and he DEFINITELY has the backpack.

By Catherine McClary

Verb: to put a backpack on a very drunk person before they go to bed, so as to keep them on their side in the recovery position and stop them from rolling onto their back so they don't choke on their vomit in their sleep

We're going to have to backpack Ally tonight and make sure to put something heavy in it because she just finished a fifth of vodka

By sassyras