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.

Definitions of lethargy

n inactivity; showing an unusual lack of energy

flatness, languor, phlegm, sluggishness
Type of:
inactiveness, inactivity, inertia
a disposition to remain inactive or inert

n weakness characterized by a lack of vitality or energy

inanition, lassitude, slackness
Type of:
the property of lacking physical or mental strength; liability to failure under pressure or stress or strain

n a state of comatose torpor (as found in sleeping sickness)

lassitude, sluggishness
mental lethargy or dullness
Type of:
torpidity, torpor
a state of motor and mental inactivity with a partial suspension of sensibility

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