Hauptschule

A "Hauptschule" (German: general school) is a secondary school in Germany and Austria, starting after 4 years of elementary schooling. Any student who went to a German elementary school can go to a Hauptschule afterwards, whereas students who want to attend a Realschule or Gymnasium need to have good marks in order to do so. The students spend five-six years at the Hauptschule, from 5th to 9th (or 10th) grade. They finish at about age 15-16.
See more at Wikipedia.org...

n. lower secondary school