When a person has a large butt and they pass gas, It's a double fart. The first is when it exits the butthole, the second when it escapes the butt cheeks.
by Anxena January 01, 2015
A fart that was meant to be farted out once, but some of the odor is trapped in the ass so you need another fart to clear it all out.
I intended to fart after eating the BLT, but it became a double fart.
by igonnafuajyama November 02, 2014