It means Dinosaur. It was used to make fun of people, because no one knows what it means and your practically calling them a Dinosaur. The 'pet' is silent on the end of Frampet. So it's pronounced Fram. You are automatically a Frampet if you don't know what it means.
GOD, YOU'RE SUCH A FRAMPET! -Ian
Your the frampet Ian. -Arfy
Your the frampet for not knowing what frampet means! -Keanan