a secondary or high school, esp. a private one.

a school or college for special instruction or training in a subject

a military academy.

an association or institution for the advancement of art, literature, or science

the National Academy of Arts and Letters.

a group of authorities and leaders in a field of scholarship, art, etc., who are often permitted to dictate standards, prescribe methods, and criticize new ideas.

the Academy,

the Platonic school of philosophy or its adherents.

academe ( def. 3 ) .

French Academy.

Royal Academy.

noun

boarding school , brainery , finishing school , halls of ivy , institute , military school , preparatory school , prep school , secondary school , seminary , alliance , association , circle , council , federation , foundation , fraternity , league , college , institution , manege , school , society , university