The definition of lethargy is drowsiness or a lack of energy.
(noun)An example of lethargy is how someone would feel after taking a sedative.
See lethargy in Webster's New World College Dictionary
noun
Origin: ME litarge < OFr < LL lethargia < Gr lēthargia < lēthargos, forgetful < lēthē (see Lethe) + argos, idle < a-, not + ergon, work
See lethargy in American Heritage Dictionary 4
noun pl. leth·ar·gies
Origin:
Origin: Middle English letargie
Origin: , from Old French
Origin: , from Late Latin lēthārgia
Origin: , from Greek lēthārgiā
Origin: , from lēthārgos, forgetful
Origin: : lēthē, forgetfulness
Origin: + ārgos, idle (a-, without; see a-1 + ergon, work; see werg- in Indo-European roots)
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