A supplementary lecture or class given to make up for missed content; often held as makeup sessions or exam preparation.
欠席した授業の補講を来週受けることになった。
I have to attend a makeup class for the lesson I missed next week.
試験前に教授が補講を増やしてくれたので、理解が深まった。
The professor increased supplementary lectures before the exam, which deepened my understanding.