[ 'lɛθədʒi ]
■ noun
1》 a lack of energy and enthusiasm.
2》 Medicine a pathological state of sleepiness or deep unresponsiveness.
Derivatives
lethargic adjective
lethargically adverb
Origin
ME: via OFr. from late L. lethargia , from Gk lēthargia , from lēthargos 'forgetful'.