adjective - of a food, having the property of increasing the production of intestinal gases. For example, cabbage, chili beans, lentils. The noun form is 'flatogen'
Dude, why'd you have to eat that chili bean burrito for lunch? Don't you know it's flatogenic? You've been farting every five minutes for the last 100 miles of this trip!
When a meat-head or bro tackles a smaller person so that he can violently rub his head on their head. The purpose of the flat dog may be homoerotic in nature.