'Bǔ kǎo' literally means 'to supplement an exam' — 'bǔ' (补) means 'to make up, to supplement, or to fill a gap', and 'kǎo' (考) means 'exam' or 'test'. Together, they refer specifically to a formal, scheduled re-examination given to students who missed the original exam due to approved reasons (e.g., illness or emergency) or who failed it and are granted a second chance under institutional policy.

This term is used almost exclusively in academic settings in China and other Mandarin-speaking regions. It is not interchangeable with informal review sessions or practice tests. A 补考 is official, graded, and often has strict eligibility requirements and deadlines. Unlike retakes in some Western systems, it usually occurs only once and at a fixed time — often before the start of the next semester — and may carry administrative consequences if missed again.