A class where there is no work done and all that you do is chill. In highschool, especially in lower grades, some classes will become chill classes for awhile. In most cases this happens because work in neglected but can also happen if all work is completed and all that is left to do is chill out.
I finished my assignment for civics five days early. So its pretty much just chill class for the rest of the week.
Person one: "What classes do you have this semester?"
Person two: "I have math, english, art and chill class.