Meaning

noun a male demon believed to lie on sleeping persons and to have sexual intercourse with sleeping women

noun a situation resembling a terrifying dream

noun someone who depresses or worries others

originFrom Late Latin incubus, from Latin incubō (“nightmare, one who lies down on the sleeper”), from incubō (“to lie upon, to hatch”, from in- (“on”) + cubō (“to lie down”)).

Etymology from Wiktionary, CC BY-SA 3.0