A dance done to mimic the dip performed by the dope heads at Kensington and Allegheny in Philadelphia's Kensington neighborhood

1. A short version of "okay"

2. A very rude, hateful way to agree or acknowledge.

K-On! (けいおん！） Is a Japanese four-panel comic strip seinen manga written and illustrated by Kakifly. The four main characters in the beginning of the story are Yui Hirasawa (Guitar), Ritsu Tainaka (Drums), Mio Akiyama (Bass), and Tsumugi Kotobuki (Keyboard). Later, Azusa Nakano (Guitar) joins the Keionbu (Hence the anime's name, K-On!).

The "Weapons" board of 4chan.
A regular poster on /k/ is usually referred to as a /k/ommando, and discussions usually involve modern weaponry, but this is by no means exclusive.
Like most other boards on the site, it is primarily likened to a river of shit with gold nuggets on the bottom. Whether or not it is worth panning is entirely up to you.

The letter people text you when they don't want to talk to you anymore.

The text you receive from your girlfriend, really meaning "fuck you"

Exactly what you do NOT reply to a long, heartfelt message sent over ANYTHING.