5.1

5.1 refers to the state you are in when you become really loud after a drinking session. The 5.1 originates from the surround sound speaker system and hence you can hear the person from every angle.

1) Easy mate you on a 5.1
2) Turn it down bruv u reachin 5.1

by Silent Assassin June 17, 2005

5.1

A type of sound system.

Barlow: Five-point-one is *RIGHT*

by Spi September 28, 2003

5.1

theory of sorround sound for speakers. does not work with headphones.

1. ) "I bought an 5.1 surroundsound headset." "Well Bro that is bullshit. It does not work.!"

by Spankmaster B November 27, 2012

5.1 inches

The average penis size on the world according to the first google result

Also see:
12.9 cm
1.5 credit cards
0.5 bycicle tires
2 Nobel prizes

Dude I heard Robert's penis is 5.1 inches
Really! Mine's only 2......Nobel prizes... O-of course.

by Adolf The One and Only May 25, 2017