Teachers can change the name of their classes to anything they want! Class names can be up to 50 characters long and are visible everywhere. However, a teacher cannot have two classes with the same name.
To change the name of a class, click on the class you wish to rename from your home screen, then click on the Settings tab.
Then type in the name you wish to view for your class in the "Class Nickname" field, and click "Save" to complete the renaming.