The Zealots were a group of Jews who lived about the same time as Jesus. The wanted to defeat the Romans, who were the rulers of Palestine at that time. They used violence to meet their goals. One of the Twelve Apostles of Jesus, named Simon, was a Zealot. The word "zealot" (not written with a capital letter) in modern English is used for any person who has a very strong idea about things and works hard to act upon their ideas. There are political and religious zealots but people can be "zealous" about other things also.