Verb
To become high by way of snorting or sniffing cat piss. Cheesing can cause a psychedelic trip where the person cheesing visits a fantasyland where they get to fornicate with the boob princess. Trey Parker and Matt Stone discovered the miracle effects of cheesing.

Adjective
To describe one who is high on cat urine.

Cheesing was the topic of episode 3 from season 12 of South Park titled "Major Boobage"

Large, beautiful breasts that are keep well consealed and initially appear to be much smaller and less impressive than they actually are until unleashed.

Finding glitches or finding an easy way to beat a game. A hole in the game like a hole on cheese.

Huffing Cat Urine. It is called Cheesing because it is Fon to Due.

It causes a euphoric state where the user hallucinates. Such hallucinations include, but are not limited to, flying through space, driving rocket cars, meeting women with rokin' tits, flying on squirrel dragons, saving said big breasted woman etc. Usually 80s heavy metal power rock is playing in the background.
You also get to fight in the Breasturary, and swim in the fountains of Varnuf with the Itty-titty fairies of Mammary Mountain, as well as fight the boob-goblin in the Gozonga Cave.

20% of students between the ages of 6 - 12 have said they have tried it at least once.

Other slang terms for cheesing:
The Cheese Game
Vitamin Cheese
Mary Jane Piss in yo face fun time.

How to tell if your child is Cheesing:
1.) Your child seems distant, preoccupied.
2.) Your child's face smells like cat urine.
3.) When you see tigers at the zoo, your child starts grinding his or her teeth.

Verb. To smile real big, like the Cheshire Cat. Probably from photography" "Say cheese!"

adj. Used to describe a person with an uncontrolable grin usually caused by a mischievious act of their own doing or as a result of drug use.

A word that went from 2 definitions to 37 definitions on UD in just one day. Thanks to Trey and Matt.