From Longman Dictionary of Contemporary Englishsecondary schoolˈsecondary ˌschool noun [countable] SESa school for children between the ages of 11 and 16 or 18 → primary school
Examples from the Corpus
secondary school• By secondary school there will be several hundred.• Many of them bring not only immigrant drive and first-generation values but a solid, if narrow, secondary school education.• Too rarely has it involved the specialist in the secondary school in regular discussion with primary colleagues. 