EtymologyHypnos is the Greek word for "sleep", derived from the Proto-Indo-European root *sup-no- meaning "sleep". In Greek mythology, Hypnos is the personification of sleep, and his name ultimately gave rise to the modern English term "hypnosis".MythologyIn Greek myth, Hypnos is usually the son of Nyx (Night), with Erebus (Darkness) sometimes named as his father. His twin brother is Thanatos, the personification of death. Both reside in the underworld under Hades. According to some accounts, Hypnos lives in a large cave from which the river Lethe (Forgetfulness) springs, and where night and day meet; this area is called the Land of Dreams. His bed is made of ebony, and at the entrance of his cave grow poppies and other sleep-inducing plants. The Roman equivalent of Hypnos is Somnus. Pausanias wrote that Hypnos was the dearest friend of the Muses.Notable ReferencesHypnos appears in several works of ancient literature, including Homeric Hymn to Hypnos and Ovid's Metamorphoses. In Homer's Iliad, Hera persuades Hypnos to put Zeus to sleep so she can aid the Greeks. Hypnos also features in art, often depicted as a young man with wings on his temples or shoulders, sometimes holding poppies or a cornucopia filled with poppies.Culural SignificanceThe name Hypnos is the origin of the word "hypnosis," coined in the 19th century from the Greek word for sleep. The study of sleep physiology and sleep disorders uses terms like "hypnotic" (sleep-inducing) and is similarly indebted to the mythological figure.Meaning: "sleep"Origin: GreekType: God/personificationUsage Regions: Greek mythologyRelated Names: Thanatos (twin brother), Somnus (Roman equivalent)