Definition of big school in English:

big school

noun

British
  • 1slang Slang (in a public school) a large room or hall used for holding school assemblies, etc.

  • 2Children's Slang, informal Informal (originally Children's slang) a school which provides the next level of a child's education, especially a secondary school.

Origin

Mid 19th century; earliest use found in Thomas Hughes (1822–1896), social reformer and children's writer.