A Dumb-o is a person who is actually intelligent but the intelligence is hidden behind the clumsiness and craziness! A Dumb-o is a great friend and thinks the weirdest thing! It is someone who listens to your problems and actually cares. They usually make fun of you and you have a lot of inside jokes about them, such as things about typos like Dipshiv and waving your palm flat up and down with five fingers out meaning "3-way" A Dumb-o has problems of their own and is extremely nice and loving and caring! But.... pretty dumb. But one of them will always find the dumbest things ever about you!
"Look! A Dumb-o just ran into a tree!"
"Dumb-o is such a dipshiv with her Allisonland accent! Not even real British!"