i Register
In some senses, ephialtes is marked as obsolete. Watch for register when choosing this word.
noun
an incubus; a nightmare
Those that were asleep it [a spirit] terrified with horrible visions; those that were waking it would strike, pull, or press, lying heavy upon them like an Ephialtes: so that there were perpetuall complaints every morning of their last nights rest through the whole Town.
name
An Athenian political figure who pioneered an early form of democracy.
Either of two Giants.