Gaseous gnascious Share definition Flag Used interchangeably to refer to both the vagina and the anus. Believed to refer to the looseness of a high-traffic vagina/anus. "Am I gonna get to put my howard Dean in your gaseous gnascious or what, bitch?" Gaseous gnascious by Pepe von Valderheimer December 10, 2006 Get the Gaseous gnascious mug.