The Collaborative International Dictionary of English v.0.48:

Languorous \Lan"guor*ous\, a. [From Languor: cf. F.
   langoureux.]
   Producing, or tending to produce, languor; characterized by
   languor. [Obs. or Poetic]
   [1913 Webster]

         Whom late I left in languorous constraint. --Spenser.
   [1913 Webster]

         To wile the length from languorous hours, and draw
         The sting from pain.                     --Tennyson.
   [1913 Webster]

WordNet (r) 3.0 (2006):

languorous
    adj 1: lacking spirit or liveliness; "a lackadaisical attempt";
           "a languid mood"; "a languid wave of the hand"; "a hot
           languorous afternoon" [syn: dreamy, lackadaisical,
           languid, languorous]

Moby Thesaurus II by Grady Ward, 1.0:

167 Moby Thesaurus words for "languorous":
   abeyant, ambling, anemic, apathetic, asthenic, benumbed, blase,
   bloodless, bored, cataleptic, catatonic, cautious, chicken,
   circumspect, claudicant, cowardly, crawling, creeping,
   creeping like snail, dead, debilitated, deliberate, dilatory,
   dopey, dormant, drooping, droopy, drugged, dull, easy, effete,
   enervated, etiolated, exanimate, faineant, faint, faintish,
   faltering, feeble, flabby, flaccid, flagging, flat, floppy,
   foot-dragging, foul, gentle, gone, gradual, groggy, gutless,
   halting, heavy, hebetudinous, hobbled, hobbling, idle, imbecile,
   impotent, in abeyance, in suspense, inactive, inanimate, indolent,
   indulged, inert, jaded, lackadaisical, laggard, languid,
   languishing, latent, lax, lazy, leaden, leisurely, lethargic,
   lifeless, limber, limp, limping, listless, logy, loose, lumbering,
   lumpish, lustless, marrowless, moderate, moribund, nerveless, numb,
   pampered, passive, phlegmatic, pithless, poking, poky, pooped,
   powerless, relaxed, reluctant, rubbery, sapless, sated, sauntering,
   sedentary, shuffling, sinewless, slack, sleeping, sleepy, slothful,
   slow, slow as death, slow as molasses, slow as slow, slow-crawling,
   slow-foot, slow-going, slow-legged, slow-moving, slow-paced,
   slow-poky, slow-running, slow-sailing, slow-stepped, sluggish,
   slumbering, smoldering, snail-paced, snaillike, soft, somnolent,
   spineless, spiritless, staggering, stagnant, stagnating, standing,
   static, strengthless, strolling, stultified, supine, suspended,
   tame, tentative, toddling, torpid, tortoiselike, tottering,
   trudging, turtlelike, unaroused, unhardened, unhurried, unnerved,
   unstrung, vegetable, vegetative, waddling, wan, weak, weakly,
   weary, world-weary