A Spanish word used to describe someone who is stubborn, big-headed, being ditzy, said or did something kinda dumb or who has crazy big hair! Lots of definitions, you just have to pay attention to the context.
Female version: Cabezona
Guber: "Se me olvidaron las llaves en el carro! Y esta encendido!"
Chela: Que cabezon! (similar to what a dummy!)