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lethargy

American  
[leth-er-jee] / ˈlɛθ ər dʒi /

noun

plural

lethargies
  1. the quality or state of being drowsy and dull, listless and unenergetic, or indifferent and lazy; apathetic or sluggish inactivity.

  2. Pathology. an abnormal state or disorder characterized by overpowering drowsiness or sleep.


lethargy British  
/ ˈlɛθədʒɪ, lɪˈθɑːdʒɪk /

noun

  1. sluggishness, slowness, or dullness

  2. an abnormal lack of energy, esp as the result of a disease

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • hyperlethargy noun
  • lethargic adjective
  • lethargically adverb

Etymology

Origin of lethargy

First recorded in 1325–75; from Late Latin lēthargia, from Greek lēthargía, equivalent to lḗtharg(os) “drowsy” + -ia -y 3 ( see Lethe, -algia); replacing Middle English litargie, from Medieval Latin litargīa, from Late Greek, Greek, as above

Explanation

Is your pet slug always this comatose, or is this display of lethargy unusual? The word lethargy describes inactivity or a lack of energy. Lethargy comes from the Greek lethargos, originally meaning “inactive through forgetfulness.” Somewhere along the way, the word lost the implication of “forgetfulness” and just ended up hanging around in bed all day. Still, lethargy doesn’t necessarily imply laziness; it can be brought about by illness and may also describe a lack of strength. Other lethargic nouns include torpor, sluggishness, and languor.

Keep Reading on Vocabulary.com

Vocabulary lists containing lethargy

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Symptoms of adder bites in dogs include pain and swelling, bruising, lethargy, drooling and vomiting.

From BBC • Apr. 24, 2026

Three days into their holiday in October, Ashley fell ill with symptoms including stomach pain, diarrhoea, vomiting, fever and extreme lethargy, Irwin Mitchell said.

From BBC • Feb. 1, 2026

Depression was assessed through a questionnaire asking about depressed mood, disinterest, restlessness or lethargy during the previous two weeks.

From Science Daily • Nov. 17, 2025

The US pontiff urged the world to rouse itself from "the fatal lethargy in which we are immersed".

From Barron's • Oct. 16, 2025

Mr. St. John came but once: he looked at me, and said my state of lethargy was the result of reaction from excessive and protracted fatigue.

From "Jane Eyre" by Charlotte Brontë