/ Dictionary / Index L lethargic: Meaning and Definition of Find definitions for: le•thar•gic Pronunciation: (lu-thär'jik), [key] — adj. of, pertaining to, or affected with lethargy; drowsy; sluggish. producing lethargy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lethargic (Thesaurus) lethal gene lethargic encephalitis Related Content Daily Word Quiz: meritocracy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language