Backflash 

When time freezes and your whole life flashes before your eyes.

John: So hows work?
Jane: Woah! My whole life just flashed before my eyes!
John: You mean a backflash....
Jane: *feeling dumb* Right.....

Backflash by Zippyvinman September 15, 2009

Backflash 

A skid-mark or stain on the gusset of underwear, either as a result of not wiping properly or an ill timed fart.

There's a nasty backflash in your boxers John, I think they may need a boil wash !

Backflash by Lonefox GD May 18, 2016

Backflash 

When a woman randomly remembers a position preferably in doggy, that gives her vagina pulsations/heartbeats thus craving to relive the moment immediately.

"I just had a backflash, you mean flashback?" Usually taking place after an intense sexual act or session that the woman remembers vividly and relives or wants to repeat

Backflash by Big Body Chuck March 6, 2022

Backblast Area Clear 

a. a military cautionary statement, when one is firing the AT-4. One looks behind them, scanning for personnel 100 meters back in a 90 degree cone, once it is clear they yell backblast area clear and fire.

b. One looks behind them, and whether it's clear or not, yells BACKBLAST AREA CLEAR, and rips a loud veracious fart.

a. READY, BACKBLAST AREA CLEAR, FIRE FIRE FIRE

b. Hey Tom, backblast area clear, RIPPPPPP HAHAHAHA

Backblast Area Clear by Military guy April 10, 2009

Koopa-Backdash-Wave-Slide-Hover-Walk-Moon-Landing 

In Super Smash Bros. Melee, characters who's walk-acceleration is lower than their traction value after wavelanding backwards can buffer a slight walk forwards to decrease the momentum lost. The walk input must be at its lowest value to perfectly execute the tech. (rough translation of inputs) Characters with low traction (Luigi) benefit worse than those with higher traction values in Melee. (i.e Gannondorf can benefit from the Koopa Backdash Wave Slide Hover Walk Moon Landing more than Luigi in terms of distance)
Youtube has more info on this.

The Koopa-Backdash-Wave-Slide-Hover-Walk-Moon-Landing can make virtually anyone feel like they are playing on ice.

Koopa-Backdash-Wave-Slide-Hover-Walk-Moon-Landing by Do_mmar September 11, 2020

korean backdash 

An advanced defensive meneuver created by the Chaiwanese. This technique requires a person to dip their head and shoulders while stepping backwards to avoid being physically hurt. Often done multiple times in succession.

Aris flew into a hotdog fueled rage after his attacks were thwarted by a masterful dance of korean backdashes.

korean backdash by vicnuggets May 30, 2018

Backfished 

When you see a shorty from behind and you think she’s valid but when she turns around she look like sherk.

Jaetel: Damnnn Cam look at the shorty over there

Cam: Damnnn shorty’s valid

*shorty turns around and smiles at Jaetel*

Jaetel: UGHHH MY EYES

Cam: Ewww shorty looks like Sherk

Jaetel: Damn bro we just got backfished

Backfished by Jaetel the G September 17, 2018