Crop Circle

When your cornrows have a bald spot.

"Snoop Dogg had to change his hairstyle so he wouldn't start getting a Crop Circle."

Port Lincoln Crop Circle

When a group of mates gather in a circle each facing the same way around the circle, front to back, drop down to a crouch, and shove an ecstasy tablet up the arse of the person in front. Then when all the pills are shelved, turn into the middle of the circle, touch fingers and say "E.T. Phone Home!"

"Me and Lockie had some mates around last night for a Port Lincoln Crop Circle. It was pretty Loose ay"

Carolina crop circle

When one person (typically male) elects to get naked and have a group of (also naked) women stand around them in a circle while they pass thier flatulent gasses in said individual's general direction for the soul purpose of sexual fulfillment.

Friend #1: "Hey Mikey, you gonna make it out for my bar mitzvah next weekend?"

Friend #2 "Sorry bro I can't make it. I'm hiring a bunch of overweight prostitutes to give me a Carolina crop circle that weekend!"