Generally, they all mean some backward-thinking, uneducated person, like someone from the country. (Not to diss country folk in general.) In most cases it's not worth splitting hairs. Boor - uncouth, uneducated (from the Dutch "boer", a farmer) Hick - short for Richard, but this connection is not made today. The modern meaning is pretty much the same as yokel. Yokel - again, related to a farmer, but a little more disparaging (German "Jokel" from the name Jakob) Bumpkin - again, about rural people but the implication is they're short and dumpy, like a little barrel. (Dutch "bommekijn"). Credits to here: www.etymonline.com

Boor means acrude uncouth ill-bred person lacking culture or refinement While Yokel,Hick,Bumpkin has the same meaning which means a person who is not very intelligent or interested in culture. cowboy...

Thank you very much. Even if I check up a dictionary, the subtle difference in nuance or usage is hard to understand.

”Country Bumpkin" would be correct. All the others are quite rude.