At uni you can do the final test of a course twice, what do you call the second test ?
Is it a second term ? No that’s the second semester isn’t it ?
When you fail you might have the option to retake an exam (also used as a noun). In British English resit is also (more?) commonly used (both as verb and noun).
In some cases they are also called supplementary exams however these can also mean exams in other subjects or from a different exam board that can replace the original exam
Edit: retest is another possibility (from comments)