fluffbutt noun6 •(US, informal) An animal with a fluffy behind, especially a cat or a dog.These two fluffbutts were busily waddling across the entrance to the apartment complex and coming very close to getting run over. Not good for their health to say the least. — 2010 •(informal, slang) A furry.Made a new adoptable base because my other one was kind of a pain to work off of. These fluffbutts are three dollars each, only taking payment via paypal. — 2011 •(slang, rare) A fluffy butt.I bet! He has an open invite to beat it like a drum for me. Once he's done he can put the fluffbutt of his against my back.Lol — 2009 •(slang, rare) A cloth-diapered bottom. •(slang, offensive) Term of abuse. •(slang, rare) One who wears a diaper; a diaperbutt. formsfluffbutts