Someone who is more than a twit... so much more. The act of describing them simply as a twit would do an injustice to the twits of the world. This person is just so frickin stupid... Like a special kind of stupid. You just want to reach across the table and backhand them, and then while they are grabbing their cheek in pain, you want to ask what on Earth made them so dumb, and ensure its not catchy.
"A woman on the bus got pissed at me when I wanted to sit down where her purse was. What a twitwich!"
"There is a twitwich convention in town, and you got, like, 3 invitations"