What does lethargic mean?
Lethargic means lacking energy, alertness, or enthusiasm, and it is often used to describe both physical sluggishness and a dull or inactive state of mind. Someone who is lethargic may move slowly, appear tired, and have difficulty concentrating or responding eagerly. The word can also characterize behavior that seems slow, ineffective, or deficient in activity, as in “a lethargic response.” Its connotation is usually mildly negative, suggesting an absence of vitality rather than ordinary rest or temporary fatigue. In medical writing, lethargic can indicate a marked reduction in activity and responsiveness. Although lethargy describes a state of reduced energy, lethargic is its corresponding adjective and is the form used when making comparisons or describing a person, condition, or pattern of behavior.
adjectiveLethargic describes a person, state, or condition characterized by a lack of energy, alertness, or willingness to act. It can also describe something slow, sluggish, or insufficiently active.
- Having little energy or alertness; sluggish and slow to act.
- Characterized by a dull, inactive, or listless quality.
"After a long flight and an early meeting, she felt lethargic and unable to concentrate."
"The lethargic dog barely lifted its head when we came through the door."
"A series of cloudy meetings left the team in a lethargic mood by the end of the afternoon."
Lethargic comes from the Greek root for forgetfulness, linking an old idea of forgetfulness with today’s familiar feeling of being drained and slow to respond.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does lethargic come from?
Lethargic comes through Latin lethargia from the Greek lethargia, a term associated with drowsiness and forgetfulness. Its deeper roots are Greek lethargos, meaning forgetful or forgetful of what is done, and the related notion of being easily forgotten. English adopted the family in the 16th and 17th centuries, with lethargy appearing earlier as a noun and lethargic developing as an adjective. The same root underlies the cognate lethargy, while the form lethargus is a less common related term.
Related word forms
How lethargic is actually used
Lethargic is commonly used for people, behavior, and physical or mental states. In medical contexts, it can describe persistent or extreme lethargy, although it is less precise than diagnoses such as hypersomnia or encephalopathy.
Easily confused with lethargic
Apathetic emphasizes an absence of interest or concern, whereas lethargic primarily emphasizes a lack of energy or physical and mental alertness.