The Collaborative International Dictionary of English v.0.48:

Sack \Sack\, n. [OE. sak, sek, AS. sacc, saecc, L. saccus, Gr.
   sa`kkos from Heb. sak; cf. F. sac, from the Latin. Cf. Sac,
   Satchel, Sack to plunder.]
   1. A bag for holding and carrying goods of any kind; a
      receptacle made of some kind of pliable material, as
      cloth, leather, and the like; a large pouch.
      [1913 Webster]

   2. A measure of varying capacity, according to local usage
      and the substance. The American sack of salt is 215
      pounds; the sack of wheat, two bushels. --McElrath.
      [1913 Webster]

   3. [Perhaps a different word.] Originally, a loosely hanging
      garment for women, worn like a cloak about the shoulders,
      and serving as a decorative appendage to the gown; now, an
      outer garment with sleeves, worn by women; as, a dressing
      sack. [Written also sacque.]
      [1913 Webster]

   4. A sack coat; a kind of coat worn by men, and extending
      from top to bottom without a cross seam.
      [1913 Webster]

   5. (Biol.) See 2d Sac, 2.
      [1913 Webster]
      [1913 Webster]

   Sack bearer (Zool.). See Basket worm, under Basket.

   Sack tree (Bot.), an East Indian tree (Antiaris
      saccidora) which is cut into lengths, and made into sacks
      by turning the bark inside out, and leaving a slice of the
      wood for a bottom.

   To give the sack to or get the sack, to discharge, or be
      discharged, from employment; to jilt, or be jilted.
      [Slang]

   To hit the sack, to go to bed. [Slang]
      [1913 Webster +PJC]

The Collaborative International Dictionary of English v.0.48:

Sack \Sack\ (s[a^]k), n. [OE. seck, F. sec dry (cf. Sp. seco,
   It. secco), from L. siccus dry, harsh; perhaps akin to Gr.
   'ischno`s, Skr. sikata sand, Ir. sesc dry, W. hysp. Cf.
   Desiccate.]
   A name formerly given to various dry Spanish wines. "Sherris
   sack." --Shak.
   [1913 Webster]

   Sack posset, a posset made of sack, and some other
      ingredients.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sack \Sack\, n. [F. sac plunder, pillage, originally, a pack,
   packet, booty packed up, fr. L. saccus. See Sack a bag.]
   The pillage or plunder, as of a town or city; the storm and
   plunder of a town; devastation; ravage.
   [1913 Webster]

         The town was stormed, and delivered up to sack, -- by
         which phrase is to be understood the perpetration of
         all those outrages which the ruthless code of war
         allowed, in that age, on the persons and property of
         the defenseless inhabitants, without regard to sex or
         age.                                     --Prescott.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sack \Sack\, v. t. [imp. & p. p. Sacked; p. pr. & vb. n.
   Sacking.] [See Sack pillage.]
   To plunder or pillage, as a town or city; to devastate; to
   ravage.
   [1913 Webster]

         The Romans lay under the apprehensions of seeing their
         city sacked by a barbarous enemy.        --Addison.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sack \Sack\, v. t.
   1. To put in a sack; to bag; as, to sack corn.
      [1913 Webster]

            Bolsters sacked in cloth, blue and crimson. --L.
                                                  Wallace.
      [1913 Webster]

   2. To bear or carry in a sack upon the back or the shoulders.
      [Colloq.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

sack
    n 1: a bag made of paper or plastic for holding customer's
         purchases [syn: sack, poke, paper bag, carrier bag]
    2: an enclosed space; "the trapped miners found a pocket of air"
       [syn: pouch, sac, sack, pocket]
    3: the quantity contained in a sack [syn: sack, sackful]
    4: any of various light dry strong white wine from Spain and
       Canary Islands (including sherry)
    5: a woman's full loose hiplength jacket [syn: sack, sacque]
    6: a hanging bed of canvas or rope netting (usually suspended
       between two trees); swings easily [syn: hammock, sack]
    7: a loose-fitting dress hanging straight from the shoulders
       without a waist [syn: chemise, sack, shift]
    8: the plundering of a place by an army or mob; usually involves
       destruction and slaughter; "the sack of Rome"
    9: the termination of someone's employment (leaving them free to
       depart) [syn: dismissal, dismission, discharge,
       firing, liberation, release, sack, sacking]
    v 1: plunder (a town) after capture; "the barbarians sacked
         Rome" [syn: sack, plunder]
    2: terminate the employment of; discharge from an office or
       position; "The boss fired his secretary today"; "The company
       terminated 25% of its workers" [syn: displace, fire,
       give notice, can, dismiss, give the axe, send away,
       sack, force out, give the sack, terminate] [ant:
       employ, engage, hire]
    3: make as a net profit; "The company cleared $1 million" [syn:
       net, sack, sack up, clear]
    4: put in a sack; "The grocer sacked the onions"

Moby Thesaurus II by Grady Ward, 1.0:

267 Moby Thesaurus words for "sack":
   acquire, assault, attack, ax, bag, balloon, banditry, barbarize,
   barrel, basket, batter, be seized of, bed, bedstead, bladder, boot,
   boot out, bottle, bounce, box, box up, break, brigandage,
   brigandism, brutalize, bump, bunk, burden, burn, bust, butcher,
   can, capsule, capture, carry on, carton, case, cashier, cashiering,
   cask, catch, chuck, come by, come in for, come into, conge,
   container, contract, corral, couch, crate, defrock, degrade,
   demote, deplume, deposal, depose, depredate, depredation, deprive,
   derive, desecrate, desolate, despoil, despoiling, despoilment,
   despoliation, destroy, devastate, devour, direption, disbar,
   discharge, disemploy, disemployment, dismiss, dismissal, displace,
   displacing, displume, doss, drag down, draw, drop, drum out,
   drumming out, earn, encase, encyst, enmesh, ensnare, entangle,
   enter into possession, entrap, expel, fill, fire, firing, fleece,
   fob, forage, foraging, foray, forced separation, foul, freeboot,
   freebooting, freight, furlough, furloughing, gain, get,
   give the ax, give the gate, go on, gurney, gut, hammer, hamper,
   harpoon, harvest, heap, heap up, hit the hay, hit the sack, hook,
   jar, kick, kick out, kick upstairs, kip, kip down, lade, land,
   lasso, lay off, lay waste, layoff, let go, let out, litter, load,
   loot, looting, make, make redundant, maraud, marauding, mass, maul,
   mesh, mug, nail, net, noose, obtain, pack, pack away, package,
   parcel, pension off, pile, pillage, pillaging, pink slip, plunder,
   plundering, pocket, poke, pot, pouch, prey on, procure, pull down,
   rage, raid, raiding, ramp, rampage, ransack, ransacking, rant,
   rape, rapine, ravage, ravagement, ravaging, rave, raven, ravish,
   ravishment, razzia, read out of, reap, reive, reiving, release,
   removal, remove, replace, retire, retirement, rifle, rifling, riot,
   roar, rope, ruin, sac, sack out, sacking, savage, score, secure,
   send packing, separate forcibly, ship, slaughter, snag, snare,
   sniggle, sofa, sow chaos, spear, spoil, spoiling, spoliate,
   spoliation, stack, store, storm, stow, stretcher, strip,
   superannuate, surplus, surplusing, suspend, suspension, sweep,
   take, tangle, tangle up with, tank, tear, tear around, terminate,
   terrorize, the ax, the boot, the bounce, the gate, the hay,
   the sack, ticket, tin, trap, turn in, turn off, turn out, unfrock,
   vandalize, violate, walking papers, waste, win, wreck