The "radius" that forms around two gay males dancing together in a straight club or bar. Ranging anywhere from 2-6 feet, the radius is characterized by an empty circular stretch of dance floor where the homosexuality can be quarantined and prevented from spreading. Often accompanied by heterosexist comments and harassment.
There is a seemingly inverse gaydius for lesbians, characterized by heterosexual men getting too close for comfort.
"Man, this dance floor is packed."
"Yeah, man, lets see if we can find a spot to dance together."
"Whoa where did all this room come from?"
"Dude... it's a gaydius. It's because your ass is in my crotch."