sleeping sickness
Preserved but no longer current.
A West African disease caused by a parasite, Trypanosoma Gambiense, characterized by fever and great sleepiness, and usually terminating fatally. The disease known in England, which shows similar symptoms is usually called Sleeping illness or Sleepy sickness as a means of distinction; its scientific name is Encephalitis lethargica.
Era: ca. 1898 (Victorian)
Sources & notes
Reproduced from Brewer’s Dictionary of Phrase and Fable (1898 edition, public domain; archive.org, retrieved 2026-07-31; OCR text, minor errors possible). Reflects the scholarship and attitudes of its era.
Common questions
What does “sleeping sickness” mean?
A West African disease caused by a parasite, Trypanosoma Gambiense, characterized by fever and great sleepiness, and usually terminating fatally. The disease known in England, which shows similar symptoms is usually called Sleeping illness or Sleepy sickness as a means of distinction; its scientific name is Encephalitis lethargica.
Is “sleeping sickness” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.