Etymology of the English word lethargy
the English word lethargy
derived from the Latin word lethargia
derived from the Greek word lethargos, λήθαργος
derived from the Greek word argos, ἀργός (inactive; unemployed; lazy, useless)
derived from the Proto-Indo-European root *arg-
derived from the Greek word lethe, λήθη (forgetfulness)
derived from the Greek word lethargia, ληθαργία