From the PC game Counter-Strike, where C1 will send a radio message 'Roger that'.

Now used in real life.
Geek 1: Man this new monitor rocks!

Geek 2: C1 on that.
by Chris January 8, 2004
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Rh0x (DEAD): man that LyNx kid is a faggot
Sh0cK(DEAD): c1
by shock March 23, 2003
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A cs-ers counter-strike way of saying "Affirmative". If you press c 1 in Counter-strike it`ll say affirmative.
someone: "Need backup"
lilgirl: "c1"
by lilgirl August 12, 2003
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Small single engined airplane made by Cessna. Generally refers to the Cessna 172, the most highly produced airplane in the world.
Bob: We flew down to LA in the C1. It was so fly.

Edith: That's ballin' bro.

Bob: They make a Gulfstream do 360s for 5 minutes while we were in the pattern to land.

Edith: That bitch in the G6 must have been way pissed.

Bob: Hella pro.
by c1pilot August 4, 2011
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When your bestfriend list On snapchat is full of the opposite gender it becomes C1 settings. You basically are a player But it’s not by choice and you Everyone knows it.
Man 1: You chat to bare girls
Man 2: yeah it’s C1 settings
Man 1: aha peakkk😂
by Quit_Dont July 29, 2020
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The example of why you need to keep a condom in you're car.
boy 1- I have a citroen c1
Boy 2 - yes have sex
boy 1- lol yes
by ben lil peen October 5, 2020
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