Osu! 

A rhythm game that requires the tapping/dragging of balls that appears on a random location of the screen, most good players are considered a virgin due to the pure skill and the amount of time they put into that game
There is a mobile version(actually I'm not sure) that has the same mechanics.

This game is normally paired with popular songs and anime backgrounds , some levels are just pure memes , and some levels are impossible to beat

"I send all my life playing osu!"

Osu! by Abosluteclown October 5, 2021

osu! 

dick

osu! lol

osu! by Collloser The Typer Boi November 5, 2021

Osu! 

A platform for dweebs and/or children to practice useful real world skills.

Steven: Wanna go out?
Dweeb: No, i'm gonna livestream Osu!
Steven: What for?
Dweeb: Heh...*le closes all crunchy roll tabs* a skill i can only show m'ladies ;3

Osu! by kakapoopooaccount December 7, 2018

osu! 

Some game where you tap triangles and hold on to big long triangles

I play osu!
- Cookiezi is fucking hot.

osu! by Hayden194 January 15, 2018

osu! 

game that eat your soul power and u will never other play for a day

A: B let play osu!

B:maybe

osu! by ueki12 May 22, 2020

osu! 

osu!, pronounced as oss or ohsuuu or idk

osu! was developed by peppy (Dean Herbert) in 2007 as a PC alternative to osu! Tatakae Ouendan.

But he well didnt know that many weebs and weird people are going to get addicted at the game and rise the high ranks with help of pp maps, and yeah...

PP stands for - Perfomance Points.

It is pretty broken so many users of the community abuse the system and create - then rank maps to make users play them, because pp maps are pretty popular, and people like dopamine from getting a high number after hundred of retries.

Dont do osu!, it is a drug.

Someone: What are you doing?
Me, an osu addict: I am playing osu!.
Someone: Oh! What rank are you?
Me, an osu addict: Almost a 4digit.
Someone: Are your hands tired?
Me, an osu addict: Yes, they are, indeed.

osu! by Doggie132Yea August 21, 2020

osu! 

That circle clicking rhythm game that also an aiming game. Based on Osu! Tatakae! Ouendan. Probably the most popular rhythm game along with Guitar Hero and DDR. Spelled with a lowercase o and an exclamation mark at the end.

A: "What do you just play?"

B: "This game I just know. It's called Osu."
A: "IT'S SPELLED osu! U IDIOT TCVBVJGY..."
B: "Haha circle goes brrrrrrrrrrrr..."

osu! by EX_ February 25, 2021