(1) - Lethargy (v. t.) To lethargize. (2) - Lethargy (n.) A state of inaction or indifference. (3) - Lethargy (n.) Morbid drowsiness; continued or profound sleep, from which a person can scarcely be awaked.
(1) - Lethe (n.) Oblivion; a draught of oblivion; forgetfulness. (2) - Lethe (n.) A river of Hades whose waters when drunk caused forgetfulness of the past. (3) - Lethe (n.) Death.