LYCÆUM, Λυκεῖον, 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. Suadas 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 Lycaeus son of Apollo; but others mention it to have been built by Pisistratus or Pericles.

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