A hard worker is someone who puts in a lot of effort and dedication to their job. This could include a SERF, who was a peasant in the Middle Ages who worked on the land of a lord; a SWOT, which is someone who studies hard; a BEAVER, which is an animal known for its hard work ethic; a Trojan, which is someone from the ancient city of Troy who was known for their hard work; a bot, which is a computer program designed to do repetitive tasks; a plier, which is a tool used for gripping and turning objects; a ROBOT, which is a machine that can be programmed to do certain tasks; a DRUDGE, which is someone who does tedious or unpleasant work; a TOILER, which is someone who works hard and long hours; and a grafter, which is someone who works hard and diligently.