This is an Old English term used by J.R.R. Tolkien to mean an unlikable, rude person. Oddly enough, such people still exist today. We call them ass$#$s. However, if you wanna clean up your language or you're somewhere where the word " ass$#$" as a human descriptor works but would be unwelcome, then "churl" is your word. It's a great way to call someone an ass$#$ without calling them... an ass$#$ and we all know plenty of those.