Bavarian Backpack 

To defecate in one's bag as a practicle joke. Best if used as a means of revenge or suprise. For greater effect, perform the deed before the victim arrives for work or school. Modeled after the infamous Doutcheland Snackbag.

Yo, he's asleep. Break out his bag, I feel a Bavarian Backpack coming on.

Bavarian Backpack by Iventor of the B.B. May 18, 2006

The Backpack Kid 

The Backpack Kid (born Russell Horning), is an American social media personality, dancer and music artist that rose to fame after he popularised the ‘floss’ dance after being featured as a backup dancer in Katy Perry’s SNL performance for “Swish Swish.” In addition to the popularisation of the ‘floss’ dance, he also gained notoriety in the meme community, after his song “Flossin’” was featured in a a Genius segment of Verified.

Random Person 1: Hey, Random Person 2! Did you check out The Backpack Kid’s new single Flossin’?
Random Person 2: Nah! That song is utter trash!

The Backpack Kid by LesGrossman@UrbanDictionary February 14, 2019

The Backpack 

The "backpack" is a sexual act in which a male stands behind a female and reaches his arms over her shoulders inserting a finger from each hand into her vagina. After insertion the male then mounts the females back assuming a "piggy back" position. After the male is airborne he continues to "finger blast" the female. *This is usually performed while dancing*

Man! Youll never believe it. i pulled the Backpack off last night at Shortys.

The Backpack by NuggFunny October 25, 2014

Backpack 

To get smacked down so hard you never get back up again. Usually used in non-digital esports, such as Magic: The Gathering, Yu-Gi-Oh!, or Pokemon. This term originates from someone trying to look at the round pairings and the neckbeard in front of them turns quickly, smashing them with a backpack full of nerd-cardboard.

I backpacked that mother fucker in round 3; he quit the whole damned tournament and sold his deck to the vendors.

Backpack by Backpack Grinder September 22, 2018

Backpacking 

When a masculine lesbian wears a backpack containing a strap on or dildo

That lesbian is backpacking

Backpacking by IrieJade October 18, 2019

Russian Backpack

When a male is having anal sex with a female and is interupted by an outside source. He proceeds to pull out so fast and with such vigor, he rips out her O ring.

Kevin was boning this girl and her parents walked in. She ended up with a russian backpack. OUCH.

Russian Backpack by McSandtrap October 5, 2005

Backpacking 

When someone on a team is getting all the kills, captures, plants, and defuses, and is the only reason that team is winning.

That kid is backpacking his team so hardcore right now.

Backpacking by Popernicle May 25, 2011