Definition of "academy"

The artists of London had long maintained a private academy for improvement in the art of drawing from living figures

1760–5, Tobias Smollett, The history of England from the revolution in 1688, to the death of George II, published 1805, page 449

In this year 1633, I became acquainted with Nicholas Fiske, licentiate in physic, who was born in Suffolk, near Framingham* Castle, of very good parentage, who educated him at country schools, until he was fit for the university; but he went not to the academy, studying at home both astrology and physic, which he afterwards practised in Colchester; and there was well acquainted with Dr Gilbert, who wrote "De Magnete".

1776, David Hume, The life of David Hume‎

Rudolf was the bold, bad Baron of traditional melodrama. Irene was young, as pretty as a picture, fresh from a music academy in England. He was the scion of an ancient noble family; she an orphan without money or friends.

1956, Delano Ames, chapter 9, in Crime out of Mind‎

In the academy and outside of it, the privileging of technical expertise above other forms of knowledge is a political gesture, and one that has proved highly effective in neutralizing critique of established power relations.

2016, Neoliberal Tools (and Archives): A Political History of Digital Humanities‎