A school for children who have completed elementary school or grade school, but are not yet old enough for high school. In the US, it often includes grades 7 and 8, and possibly also 6 or 9.
Middle school; junior high school; a school that one attends between the ages of 12-17 (equivalent of grades 7-10 in North America, and years 7-10 in Australia).
School with education level between primary school and university.
In the UK and Ireland, a state school attended between the ages of 11 and 16 or 18.
The federally designated, graduation-separated classification of grades 9–12 (approximately ages 14–18), regardless of whether they are compiled together in one school or separate from the other grades.