Definition of ephialtes in English:
noun (plural same)rare
- The black seed also taken before bedtime, is very effectual for such as in their sleep are troubled with the disease called Ephialtes.
- The ephialtes, or nightmare, is called by the common people witch-riding.
- To prevent the Ephialtes or night-mare we hang up a hollow stone in our stables.
early 17th century: Greek ephialtēs, possibly from ephiallesthai 'leap on'.