private school (US), public school (UK)

military academy, (especially) the Imperial Japanese Naval Academy

complete denial of knowing (an incident in question)

(historical) elementary school, national elementary school

school supported by a pro-South Korean organization

school supported by a pro-North Korean organization

to know through one's own experience

school grammar / (specifically) Japanese school grammar, based on Shinkichi Hashimoto's work and now universally employed in Japanese schools and dictionaries.

school for special needs

to have no way of knowing; to be completely ignorant of