kacknerd
A kacknerd is someone who thinks they're the smartest person in the room but is actually just loud and wrong. They're like a blind man trying to drive a car.
My uncle is a kacknerd. He said he could fix the internet, but now my phone doesn’t work and my mom’s fridge is yelling at him.
That girl in my class is a kacknerd. She said she could beat anyone at chess, but she lost to a kid who had a broken watch.
My dad is a kacknerd. He told the whole family he invented the wheel, but now he’s stuck in the past with a donkey.