n (classical studies|usually|capitalized) The garden where Plato taught. (defdate|First attested around 1350 to 1470.)Brown, Lesley, ed. The Shorter Oxford English Dictionary. 5th. Oxford: Oxford University Press, 2003.
n (classical studies|usually|capitalized) Plato's philosophical system based on sketpicism; Plato's followers. (defdate|First attested in the mid 16th century.)
n An institution for the study of higher learning; a college or a university; typically a private school. (defdate|First attested in the mid 16th century.)
n A school or place of training in which some special art is taught. (defdate|First attested in the late 16th century.)
n A society of learned men united for the advancement of the arts and sciences, and literature, or some particular art or science. (defdate|First attested in the early 17th century.)
n (obsolete) The knowledge disseminated in an Academy. (defdate|Attested from the early 17th century until the mid 18th century.)
n (context|with the|without reference to any specific academy)academia | Academia.
n A body of established opinion in a particular field, regarded as authoritative.