Hypnos comes from the name of his Latin counterpart, Somnus. (in- "not" + somnus "sleep"), as well as a few less-common words such as "somnolent", meaning sleepy or tending to cause sleep and hypersomnia meaning excessive sleep, which can be caused by many conditions (known as secondary hypersomnia) or a rare sleep disorder causing excessive sleep with unknown cause, called Idiopathic Hypersomnia. 3D model of "Bronze head of Hypnos" via laser scan of a cast of British Museum's bronze. Hypnos In Greek mythology, Hypnos (; , "sleep") is the personification of sleep; the Roman equivalent is known as Somnus. In the
Greek mythology comprehensive summary of Cicero's line of thought. In Ancient Roman times, a new Roman mythology was born through syncretization of numerous Greek and other foreign gods. This occurred because the Romans had little mythology of their own, and inheritance of the Greek mythological tradition caused the major Roman gods to adopt characteristics of their Greek equivalents. The gods Zeus and Jupiter are an example of this mythological overlap. In addition to the combination of the two mythological traditions, the association of the Romans with eastern religions led to further syncretizations. For instance, the cult of Sun was introduced in Rome