In Super Smash Bros., the side special move (also commonly called forward B, side B, smash B, or over B) is a special attack performed by pressing the special move button with the control stick held left or right.
Link's Side B allows you to throw a boomerang at your enemies.

Kirby's Side B allows you to smash enemies with his hammer.

Snake's Side B allows you to launch a missile from his Nikita.
by ReKuTo November 11, 2019
Recycling the usage of your dirty undergarment by flipping it inside-out on it's "side B" which is supposedly cleaner than it's "side A". People who're lazy to do their laundry do this all the time.
"Dude isn't that the same Calvin Klein undies you were wearing yesterday when we went to the beach?"

"Don't worry man, it's on it's Side B"

"That's just gross dude..."
by JBarry May 11, 2008
A b-side was originally known as the song on the flipside of a 12" or 7" vinyl single that backed the A-side, but wasn't the song promoted or received the radio play. Today CD singles have b-sides along with remixes, even though ironically CD singles only have one side that is used. With CD singles dying a slow death today, b-sides are becoming a rarer commodity. B-sides were originally used to make a single worth the buyer's money and to get fans to buy the singles along with the album it came from.

B-sides are usually songs that do not appear on the actually album that the A-side appears on, ocassionally it does. The b-side song was usually determined not to fit in with the overall sound of the album or it was considered not good enough to be on the album or just plain leftover tracks, so hence it's usage as a b-side. B-sides have often gotten a reputation of being filler and sub-par, even though a good majority of the time b-sides are better than a lot of the album tracks, and in some cases, better than the A-side.
"Autumn Goodbye" is the b-side to Britney Spears' 1999 single "...Baby One More Time."

"Heartbreaker" is the b-side to P!nk's 2006 single "Stupid Girls."
by starsinthetwilight February 20, 2009
The other song that isn't the "hit" (A side) on a 45 (7inch) piece of vinyl. Less popular second choice. Often coveted by audiophiles for its rareness. Also known as the flipside.
"Dude, which Cure album is that from?"
"It's a bunch of b sides from their singles."
"Wicked."
"Totally."
by modross March 3, 2008
The reverse side of a phonograph record, especially a single.
How many songs are you planning to record and will all of them go on the album or will some be used as b-sides?
by illEATurHARTout May 20, 2004
1-The less popular side of a record, usually featuring a song that is not promoted with the record.

2-The significantly more difficult version of a game.
1- “I personally think this record’s B-Side is super underrated, maybe even better than the A-Side.”

2- “Celeste’s B-Side levels are so difficult, I easily died 3,000 times between them all!”