Balloon 

A balloon filled with nitrous oxide, or NOS (laughing gas). You can usually find balloon dealers outside parties, raves, music festivals or other such gatherings. As soon as people hear a dealer inflating a balloon they flock round them like sheep. Balloons are the second most popular drug in the UK (aside from weed). Also goes by the name of Hippy crack.

Dealer: You came to buy balloons bruv?
Client: Yea man (hands over cash)
Dealer: Calm G, this is 100% medical grade NOS. This shit'll make you trip. (Loudly inflates balloon)

Balloon by dankcuddlybear October 29, 2018

Balloon 

A very weird thing that is basically a colored plastic sack of your breath to give your friend on their birthday.

"Here's a balloon for you!"

Balloon by Ekker October 14, 2014

Balloon 

Heroin supplier; a penny balloon that contains narcotics

Balloon by Lehem October 18, 2003

Balloon 

A fool; a person who has just made a pretty obvious mistake

PhD student 1: I forgot to correct for path length in these absorbance measurements.
PhD Student 2: You total balloon

PhD student: I left my cash card in Centra last week and only found out today
Supervisor: <Says nothing and draws a picture of a balloon on a piece of paper>

Balloon by UrbanBiochemist October 31, 2011

Balloon 

A airhead, A stupid person who floats/follows people around on a "string" like a bitch

Christian is a balloon

Balloon by goatbanger November 9, 2017

balloon 

a heroin dealer

man im out of dope i need to go to the balloon

balloon by afroman April 17, 2002

balloon 

slang for condom; slang for protection during sex.

I gotta get a balloon on before my girl gets outta the bathroom.

balloon by The Evster September 5, 2008