the basic level of a subject taken in school
"Many students choose to take three GCSEs before moving on to their A-level subjects."
Initialism of General Certificate of Secondary Education: a British qualification taken by secondary school students in England, Wales and Northern Ireland.
"Many teenagers study hard to pass their GCSEs before moving on to A-levels."
In plain English: GCSE is an exam that students take at age 16 to finish their high school education and get into college or work.
"She passed her GCSEs with high grades and is now applying to university."