1. a lack of energy and enthusiasm: "there was an air of lethargy about him"
▪ a pathological state of sleepiness or deep unresponsiveness and inactivity:"a history of weight loss, lethargy, and fluid retention"
Word Originlate Middle English: via Old French from late Latin lethargia, from Greek lēthargia, from lēthargos ‘forgetful’, from the base of lanthanesthai ‘forget’.