Early 19th century. As noun from post-classical Latin antephialtica (plural) remedies against nightmare, use as noun of neuter plural of antephialticus.
Definition of antephialtic in US English:
antephialtic
nounˌantɛfɪˈaltɪk
Something which prevents nightmares. rare.
Origin
Early 19th century. As noun from post-classical Latin antephialtica (plural) remedies against nightmare, use as noun of neuter plural of antephialticus.