Adjective combining the word, full, from the phrase "full of sh*t" with the word; hilarious. Used to express what you think of someone when they try to convince you of something that is totally absurd or when they try to trick you or get away with something and have to eat their own words or it blows up in their face.
When my friend Amy and I had a run-in with someone who was pulling our chain or tried to get away with something, we said, You're fularious!", to show them we knew what they were all about. They thought they could actually pull it off but couldn't. HA!