From Longman Dictionary of Contemporary Englishform teacherˈform ˌteacher noun [countable] British English SECthe teacher who is responsible for all the students in the same class at a school
Examples from the Corpus
form teacher• Or at the very least Big Brother himself, who sounds more like a harassed fourth form teacher than an omnipotent dictator.• That opinion really shocked me, coming from my own form teacher. 