boost slap 

a loud rev of an engine equipped with a turbo-charger, making a high pitch noise emitted through the blow-off valve and or waste-gate.

Damn i just got boost slapped by that sweat ass Eagle Talon!

boost slap by Hated Honda February 18, 2011

boot slap 

when you shit on someones ass then kick them with your boot. Leaving a boot print on their ass in poo.

Last night i fucked jen then boot slaped then boot slaped the hell out of her.

boot slap by xpunx December 4, 2004

boot slapping 

a dance move; done by a fan of industrial music or Rivet-heads(look up definition).Rivet-head's often wear garb such as old army boots, giving a slap with the palm of the hand while dancing. dance popular among rivet-heads, performed chiefly to industrial or electronic based music.

Rivet-heads began boot slapping to show off their dance moves.

boot slapping by CG roxane October 3, 2007

Boot Slapper

Soldiers must dig a 12" cat hole with their entrenching tool to defecate in the woods. When you drop a turd too long and hard for the cathole you dug for it, it inevitably topples sideways onto your boot.

Q: Did everything come out all right?
A: it was a real boot slapper

Boot Slapper by all american 82 July 8, 2011

bootslapping 

“Bootslapping: to express political displeasure by throwing footwear.”

Source: Macintyre, Ben. "Who Puts the Boot Into the Shoe Throwers?" The Times Online, February 5, 2009.
http://www.timesonline.co.uk/tol/comment/columnists/ben_macintyre/article5663234.ece

Subsequent to the incident where an Iraqi threw his shoes at George W. Bush, bootslapping became a frequent expression of public protest.

bootslapping by AVilaEditor February 6, 2009