incubus

Etymology

It is inherited from Middle English incubus,^[2][3][4] borrowed from Late Latin incubus,^[5][6][7][8] found in Augustine,^[5] an alteration of Latin incubō (“nightmare; one who lies down on the sleeper”),^{[4][6][9][10]} a noun from the verb meaning to lie upon,^[5][6][3] the source of incubate, which is formed from in- (“on”) and cubō (“to lie down”).^[4] Compare French incube, recorded in the 14th century.^[5] Its feminine counterpart is succubus.^[8][6][11]

Earliest recorded meaning

A demon that lies on people in their sleep and has intercourse with women: about 1275, in the Caligula manuscript of Laȝamon's Brut, a text perhaps from before 1200.^[5][2] Dictionary.com dates it to 1175–1225,^[12] Etymonline to about 1200,^[6] and Merriam-Webster Unabridged to the 13th century;^[3] Barnhart dates the same Laȝamon record to probably about 1350,^[9] and Hoad gives the 14th century.^[13]

Semantic evolution

The Latin word named the nightmare itself, which was thought of as someone lying on the sleeper, and in the Middle Ages it was often pictured as a malignant demon.^[5][9] Scribonius, in the 1st century, describes it as a medical condition to be treated with herbs, the English equivalent being the mare of nightmare.^[6] A text of about 1330 explains that such spirits shame women, "Incuby demones ys cald ther name",^[11] and the Middle English Dictionary also records its use for a monstrous but mortal creature only falsely supposed to be a demon.^[2] Chaucer uses the word once.^[14] The medical sense "nightmare", a feeling of weight on the chest in sleep, is recorded from 1561,^[5] and it is the only sense in Johnson (1755), who quotes Floyer's account of it as an inflation of the membranes of the stomach.^[15] From this the word passed in 1648 to any person or thing that weighs on one like a nightmare;^[5][13] Etymonline finds a softened use, "phantom; burden", by 1834.^[6] The OED also records Incubus as the name of a genus of parasitic insects,^[5] and in 1997 Reebok released a women's athletic shoe by this name.^[6]

Timeline

• c. 1275 – an evil spirit that descends on sleepers.^[5][2]
• 1561 – the nightmare, a feeling of a heavy weight on the chest during sleep.^[5]
• 1648 – a person or thing that oppresses like a nightmare.^[5]

Meanings

Noun

1. In folklore, an evil spirit believed to lie on people in their sleep, especially a male demon having sex with sleeping women: The villagers blamed an incubus for the girl's strange dreams.^[16][3][5]
2. A person or thing that oppresses or burdens one like a bad dream, such as an obsession: the incubus of the old debt.^[16][3][5]
3. A nightmare, or the feeling of a heavy weight on the chest during sleep.^[3][5][7]

Related words

• succubus
• incubate
• incubation
• cubicle

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
3. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
4. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
5. ^ a b c d e f g h i j k l m n o Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
6. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
8. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ a b c Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
10. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
11. ^ a b Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
12. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
13. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
14. ^ Benson, Larry D., Glossarial Concordance to Middle English (Chaucer, Gower), Johns Hopkins University, github.com/jhu-digital-manuscripts/gcme
15. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
16. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins