text: The 5th century Buddhist philosopher, Buddhaghosa explains that their name derives from the myth of their defeat at the hands of the god Śakra. According to the story, the asura were dispossessed of their state in Trāyastriṃśa because they became drunk and were thrown down Mount Sumeru. After this incident, they vowed never to drink sura again. In some Buddhist literature, they are sometimes referred to as pūrvadeva (Pāli: pubbadeva), meaning "ancient gods."
  Modern theories
  Monier-Williams traces the etymological roots of asura () to asu (), which means 'life of the spiritual world' or 'departed spirits'.
  In the oldest verses of the Samhita layer of Vedic texts, the Asuras are any spiritual, divine beings including those with good or bad intentions, and constructive or destructive inclinations or nature. In later verses of the Samhita layer of Vedic texts, Monier Williams states the Asuras are "evil spirits, demons and opponents of the gods". Asuras connote the chaos-creating evil, in Indo-Iranian mythology about the battle between good and evil.
  According to Finnish Indologist Asko Parpola, the word Asura was borrowed from Proto-Indo-Aryan into Proto-Uralic during an early period of contact, in the form *asera-, showing a meaning "lord, prince".
  In Hindu literature