The Collaborative International Dictionary of English v.0.48:

Empty \Emp"ty\ (?; 215), a. [Compar. Emptier; superl.
   Emptiest.] [AS. emtig, [ae]mtig, [ae]metig, fr. [ae]mta,
   [ae]metta, quiet, leisure, rest; of uncertain origin; cf. G.
   emsig busy.]
   1. Containing nothing; not holding or having anything within;
      void of contents or appropriate contents; not filled; --
      said of an inclosure, or a container, as a box, room,
      house, etc.; as, an empty chest, room, purse, or pitcher;
      an empty stomach; empty shackles.
      [1913 Webster]

   2. Free; clear; devoid; -- often with of. "That fair female
      troop . . . empty of all good." --Milton.
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            I shall find you empty of that fault. --Shak.
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   3. Having nothing to carry; unburdened. "An empty messenger."
      --Shak.
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            When ye go ye shall not go empty.     --Ex. iii. 21.
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   4. Destitute of effect, sincerity, or sense; -- said of
      language; as, empty words, or threats.
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            Words are but empty thanks.           --Cibber.
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   5. Unable to satisfy; unsatisfactory; hollow; vain; -- said
      of pleasure, the world, etc.
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            Pleas'd in the silent shade with empty praise.
                                                  --Pope.
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   6. Producing nothing; unfruitful; -- said of a plant or tree;
      as, an empty vine.
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            Seven empty ears blasted with the east wind. --Gen.
                                                  xli. 27.
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   7. Destitute of, or lacking, sense, knowledge, or courtesy;
      as, empty brains; an empty coxcomb.
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            That in civility thou seem'st so empty. --Shak.
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   8. Destitute of reality, or real existence; unsubstantial;
      as, empty dreams.
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   Note: Empty is used as the first element in a compound; as,
         empty-handed, having nothing in the hands, destitute;
         empty-headed, having few ideas; empty-hearted,
         destitute of feeling.

   Syn: See Vacant.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Empty \Emp"ty\, n.; pl. Empties.
   An empty box, crate, cask, etc.; -- used in commerce, esp. in
   transportation of freight; as, "special rates for empties."
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Empty \Emp"ty\, v. t. [imp. & p. p. Emptied; p. pr. & vb. n.
   Emptying.]
   To deprive of the contents; to exhaust; to make void or
   destitute; to make vacant; to pour out; to discharge; as, to
   empty a vessel; to empty a well or a cistern.
   [1913 Webster]

         The clouds . . . empty themselves upon the earth.
                                                  --Eccl. xi. 3.
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The Collaborative International Dictionary of English v.0.48:

Empty \Emp"ty\, v. i.
   1. To discharge itself; as, a river empties into the ocean.
      [1913 Webster]

   2. To become empty. "The chapel empties." --B. Jonson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

empty
    adj 1: holding or containing nothing; "an empty glass"; "an
           empty room"; "full of empty seats"; "empty hours" [ant:
           full]
    2: devoid of significance or point; "empty promises"; "a hollow
       victory"; "vacuous comments" [syn: empty, hollow,
       vacuous]
    3: needing nourishment; "after skipped lunch the men were empty
       by suppertime"; "empty-bellied children" [syn: empty,
       empty-bellied]
    4: emptied of emotion; "after the violent argument he felt
       empty"
    n 1: a container that has been emptied; "return all empties to
         the store"
    v 1: make void or empty of contents; "Empty the box"; "The alarm
         emptied the building" [ant: fill, fill up, make full]
    2: become empty or void of its content; "The room emptied" [syn:
       empty, discharge] [ant: fill, fill up]
    3: leave behind empty; move out of; "You must vacate your office
       by tonight" [syn: vacate, empty, abandon]
    4: remove; "Empty the water"
    5: excrete or discharge from the body [syn: evacuate, void,
       empty]

Moby Thesaurus II by Grady Ward, 1.0:

354 Moby Thesaurus words for "empty":
   abandoned, absurd, aimless, airy, apparently sound, arid, asinine,
   awkward, banal, bare, barren, baseless, blah, bland, blank,
   blankminded, bleached, bleed, bloodless, blow, blow out, bootless,
   broach, callow, calm, cast out, casuistic, catchpenny,
   characterless, cheap, clean, clean out, clear, clear away,
   clear off, clear out, clear the decks, cold, colorable, colorless,
   counterproductive, dead, deadpan, decant, deceptive, defecate,
   deplete, depleted, deserted, designless, desolate, destitute,
   destitute of, devoid, devoid of, discharge, dishonest,
   disingenuous, dismal, dog-hungry, draft, draft off, draggy, drain,
   drain out, drained, draw, draw from, draw off, drearisome, dreary,
   dry, dryasdust, dull, dumb, dump, dusty, effete, eject,
   elephantine, eliminate, emptied, empty of, empty out, empty-headed,
   empty-minded, empty-pated, empty-skulled, etiolated, evacuate,
   exhaust, exhausted, expressionless, fade, fallacious, famished,
   famishing, fasting, fatuitous, fatuous, featureless, feckless,
   find vent, fishy, flat, flimsy, flow, flow out, foolish, forsaken,
   fribble, fribbling, frivolous, frothy, fruitless, futile, garbled,
   gauche, glassy, godforsaken, green, groping, groundless, gush,
   gush out, half-famished, half-starved, heavy, ho-hum, hollow,
   hungering, hungry, hypocritical, idle, ignorant, ill-founded,
   illusive, impassive, importless, in want of, inadequate, inane,
   incogitant, ineffective, ineffectual, inefficacious, inexcitable,
   inexcusable, inexperienced, inexpressive, innocent, inoperative,
   insignificant, insincere, insipid, insubstantial, invalid, jejune,
   jesuitic, jet, know-nothing, leaden, let, let blood, let out,
   lifeless, light, low-spirited, mealymouthed, meaningless, milk,
   naive, nescient, new, nirvanic, nonconnotative, nondenotative,
   nugacious, nugatory, null, null and void, oblivious, of no force,
   otiose, outflow, outpour, overrefined, oversubtle, pale, pallid,
   paltry, passive, peckish, pedestrian, petty, phatic,
   philosophistic, phlebotomize, pinched with hunger, pipette,
   plausible, plodding, pointless, poker-faced, poky, ponderous, pour,
   pour out, pump, pump out, purge, purportless, purposeless, put out,
   quietistic, rattlebrained, rattleheaded, ravening, ravenous, raw,
   relaxed, remove, run out, sans, scatterbrained, scour out,
   scrambled, senseless, shallow, sharp-set, silly, simple,
   siphon off, slender, slight, slow, sluice out, solemn, sophistic,
   sophistical, specious, spent, spew out, spiritless, spout,
   spout out, spurt, stark, starved, starving, sterile, stiff, stodgy,
   strange to, stuffy, stupid, suck, suck out, superficial,
   superfluous, supernumerary, surge, surplus, sweep out, take away,
   take out, tap, tasteless, tedious, tentative, thoughtfree,
   thoughtless, throw out, tongue in cheek, tranquil, trifling, trite,
   trivial, unacquainted, unadorned, unapprized, unavailing, unbased,
   uncandid, unclog, uncomprehending, unconversant, undecorated,
   unenlightened, unexpressive, unfamiliar, unfilled, unfoul,
   unfounded, unfrank, ungrounded, unideaed, unilluminated,
   uninformed, uninhabitable, uninhabited, uninitiated,
   unintellectual, unintelligent, unknowing, unlively, unload,
   unmeaning, unoccupied, unposted, unreasoning, unrelieved, unripe,
   unsatisfying, unserious, unsignificant, unsupportable, unsupported,
   unsure, unsustainable, unsustained, untenable, untenanted,
   unthinking, unused, unversed, unwarranted, useless, vacant, vacate,
   vacuous, vain, valueless, vapid, venesect, vent, void, vomit forth,
   voracious, wanting, waste, well, well out, white, wild, windy,
   with nothing inside, without, without basis, without content,
   without foundation, wolfish, wooden, worthless