The Collaborative International Dictionary of English v.0.48:

Sluggard \Slug"gard\, n. [Slug + -ard.]
   A person habitually lazy, idle, and inactive; a drone.
   [1913 Webster]

         Go to the ant, thou sluggard; consider her ways, and be
         wise.                                    --Prov. vi. 6.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sluggard \Slug"gard\, a.
   Sluggish; lazy. --Dryden.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sluggard
    n 1: an idle slothful person [syn: sluggard, slug]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "sluggard":
   bum, clock watcher, dallier, dawdle, dawdler, diddler,
   dillydallier, do-nothing, dolittle, doodler, drone, faineant,
   foot-dragger, gentleman of leisure, goldbrick, goldbricker,
   goof-off, idler, laggard, lazybones, lie-abed, lingerer, loafer,
   loiterer, loller, lotus-eater, lounger, lubber, mope, moper,
   plodder, potterer, procrastinator, putterer, shirker, sleepyhead,
   slouch, sloucher, slow goer, slow-foot, slowbelly, slowpoke, slug,
   slugabed, snail, stick-in-the-mud, time killer, time waster,
   tortoise, trifler, waiter on Providence