You may not find baddest in the dictionary, but it is very much in use out there in the world of entertainment. Worst is, of course, the third in this trio – bad , worse and worst; and they need no explanation. Baddest, a modern creation, means the most bad or meanest, as in the baddest gunman, the baddest fighter etc. If we were to say the worst, it would just mean that the gunman was a lousy shot, or the fighter couldn’t fight. Language is changing all the time, and it bothers grammarians like me, but I have to accept that these days kid usually means child, not baby goat; that cool usually means really nice, not chilly; that crucial usually means great, not vital; that default means factory settings, and not failing to pay back a loan. Funny old life, isn’t it?