When you try to lie to the world and yourself, but your brain decides to take a shit instead.
Also called a "freudian shit" (the brain-hemorrage version of freudian slips).
"Despite the constant negative press covfefe"
-Tweet by Donald J. Trump, President of the United States
"Johnny, what are you doing? Have you written your essay?"
"No."
"What?! Then do it!"
"Covfefe. I mean yes. It has the best words in it."
-Johnny wanted to copy Pence's homework at school