'Lethargic' definitions:

Definition of 'lethargic'

From: WordNet
adjective
Deficient in alertness or activity; "bullfrogs became lethargic with the first cold nights" [syn: lethargic, unenrgetic] [ant: energetic]

Definition of 'Lethargic'

From: GCIDE
  • Lethargic \Le*thar"gic\ (l[-e]*th[aum]r"j[i^]k), Lethargical \Le*thar"gic*al\ (-j[i^]*kal), a. [L. lethargicus, Gr. lhqargiko`s: cf. F. l['e]thargique. See Lethargy.] Pertaining to, affected with, or resembling, lethargy; morbidly drowsy; dull; heavy. -- {Le*thar"gic*al*ly}, adv. -- {Le*thar"gic*al*ness}, n. -- {Le*thar"gic*ness}, n. [1913 Webster]