incubus

[in-kyuh-buh s, ing-] /ˈɪn kyə bəs, ˈɪŋ-/
noun, plural incubi
[in-kyuh-bahy, ing-] /ˈɪn kyəˌbaɪ, ˈɪŋ-/ (Show IPA), incubuses.
1.
an imaginary demon or evil spirit supposed to descend upon sleeping persons, especially one fabled to have sexual intercourse with women during their sleep.
Compare succubus (def 1).
2.
a nightmare.
3.
something that weighs upon or oppresses one like a nightmare.
Origin
1175-1225; Middle English < Late Latin: a nightmare induced by such a demon, noun derivative of Latin incubāre to lie upon; see incubate
Can be confused
incubus, succubus.
Examples from the web for incubus
  • It is, however, an incubus for some three dozen of the world's poorest countries.
  • It shall be one of my cherished objects to remove this incubus of our prosperity.
  • The steep decline in state capabilities amounts, on its own, to another important element in the incubus of terrorism.
British Dictionary definitions for incubus

incubus

/ˈɪnkjʊbəs/
noun (pl) -bi (-ˌbaɪ), -buses
1.
a demon believed in folklore to lie upon sleeping persons, esp to have sexual intercourse with sleeping women Compare succubus
2.
something that oppresses, worries, or disturbs greatly, esp a nightmare or obsession
Word Origin
C14: from Late Latin, from incubāre to lie upon; see incubate
Word Origin and History for incubus
n.

c.1200, from Late Latin (Augustine), from Latin incubo "nightmare, one who lies down on (the sleeper)," from incubare "to lie upon" (see incubate). Plural is incubi. In the Middle Ages their existence was recognized by law.

incubus in Medicine

incubus in·cu·bus (ĭn'kyə-bəs, ĭng'-)
n. pl. in·cu·bus·es or in·cu·bi (-bī')

  1. An evil spirit believed to have sexual intercourse with women as they sleep.

  2. A nightmare.

  3. An oppressive or nightmarish burden.