1. A natural greasy material that appears naturally in an animal's body, especially under the skin and around organs.
2. Used to describe something that has an excessive amount of body fat or is just overweight.
3. The word that is used to combat the insult "kys" (kill yourself), introduced by the popular YouTuber, Pyrocynical.
Fat Man: I have so much fat under my belly!
Random kid: Kys
Fat Man: Fat
Fat is a word that can mean anything and everything. A person is able to call anything Fat and get away with it.
That thing test was fat as. Don't be a fat man.