Origin: Anc Greek λήθαργος/lethargos (=awareness) >
Λήθη/lethe (= forgetfulness)
Lethargy is a state of awareness. Lethargy in common usage may mean also fatigue, drowsiness (sleepiness), tiredness, listlessness, or weakness.
1. In Greek mythology, Lethe is one of the fivel rivers of Hades. Those who drank from river Lethe experienced complete forgetfulness.
2. In Classical Greek, the word Lethe means «oblivion»/αμνησία", (=forgetfulness). It is related to the Greek word for "truth", αλήθεια/aletheia (=truth).
3. Orphic Hymn 85 to Hypnus (trans.
) (Greek hymns C3rd B.C. to 2nd A.D.): Taylor
"Thanatos (Death), and Lethe (Forgetfulness) with oblivious stream, mankind thy [Hypnos'] genuine brothers justly deem."