Taking a perfectly good piece of meat then placing it over a very hot flame and cooking the shit out of it until there is no flavor left. You are left with a brown or black hunk of something that only loosely resembles meat.

Most steak-puritans will agree that well done is no way to eat a steak. In some steak houses they will refuse to serve you a steak well done. A steak cooked well done is usually quite dry, and is brown in color all the way through.