LYCÆUM, Λύκειον, in antiquity, the name of a celebrated school or academy at Athens, where Aristotle explained his philosophy. The place was composed of porticoes and trees planted in the quincunx form, where the philosophers disputed walking. Hence philosophy of the Lyceum is used to signify the philosophy of Aristotle, or the Peripatetic philosophy. Suidas observes, that the Lyceum took its name from its having been originally a temple of Apollo Lyceus; or rather a portico or gallery built by Lyceus son of Apollo; but others mention it to have been built by Philetus or Pericles.

LYCÆUS, in Ancient Geography, a mountain of Arcadia, sacred to Jupiter; whence Jupiter Lyceus (Pliny). Sacred also to Pan (Virgil); and hence Lycea, the rites performed to Pan on this mountain; which Evander carrying with him to Latium, were called Lupercalia (Virgil).