The Collaborative International Dictionary of English v.0.48:

Pack \Pack\ (p[a^]k), v. t. [imp. & p. p. Packed (p[a^]kt); p.
   pr. & vb. n. Packing.] [Akin to D. pakken, G. packen, Dan.
   pakke, Sw. packa, Icel. pakka. See Pack, n.]
   1. To make a pack of; to arrange closely and securely in a
      pack; hence, to place and arrange compactly as in a pack;
      to press into close order or narrow compass; as, to pack
      goods in a box; to pack fish.
      [1913 Webster]

            Strange materials packed up with wonderful art.
                                                  --Addison.
      [1913 Webster]

            Where . . . the bones
            Of all my buried ancestors are packed. --Shak.
      [1913 Webster]

   2. To fill in the manner of a pack, that is, compactly and
      securely, as for transportation; hence, to fill closely or
      to repletion; to stow away within; to cause to be full; to
      crowd into; as, to pack a trunk; the play, or the
      audience, packs the theater.
      [1913 Webster]

   3. To shuffle, sort and arrange (the cards) in a pack so as
      to secure the game unfairly; to stack[3] (the deck).
      [1913 Webster +PJC]

            And mighty dukes pack cards for half a crown.
                                                  --Pope.
      [1913 Webster]

   4. Hence: To bring together or make up unfairly and
      fraudulently, in order to secure a certain result; to
      stack[3]; as, to pack a jury or a caucus.
      [1913 Webster]

            The expected council was dwindling into . . . a
            packed assembly of Italian bishops.   --Atterbury.
      [1913 Webster]

   5. To contrive unfairly or fraudulently; to plot. [Obs.]
      [1913 Webster]

            He lost life . . . upon a nice point subtilely
            devised and packed by his enemies.    --Fuller.
      [1913 Webster]

   6. To load with a pack; hence, to load; to encumber; as, to
      pack a horse.
      [1913 Webster]

            Our thighs packed with wax, our mouths with honey.
                                                  --Shack.
      [1913 Webster]

   7. To cause to go; to send away with baggage or belongings;
      esp., to send away peremptorily or suddenly; to send
      packing; -- sometimes with off; as, to pack a boy off to
      school.
      [1913 Webster]

            He . . . must not die
            Till George be packed with post horse up to heaven.
                                                  --Shak.
      [1913 Webster]

   8. To transport in a pack, or in the manner of a pack (i. e.,
      on the backs of men or beasts). [Western U.S.]
      [1913 Webster]

   9. (Hydropathy) To envelop in a wet or dry sheet, within
      numerous coverings. See Pack, n., 5.
      [1913 Webster]

   10. (Mech.) To render impervious, as by filling or
       surrounding with suitable material, or to fit or adjust
       so as to move without giving passage to air, water, or
       steam; as, to pack a joint; to pack the piston of a steam
       engine.
       [1913 Webster]

   11. To cover, envelop, or protect tightly with something;
       specif. (Hydropathy), to envelop in a wet or dry sheet,
       within numerous coverings.
       [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

packed \packed\ adj.
   1. Same as jammed.

   Syn: full, jammed, jam-packed.
        [WordNet 1.5]

   2. Crowded; as, the theater was packed.
      [PJC]

WordNet (r) 3.0 (2006):

packed
    adj 1: filled to capacity; "a suitcase jammed with dirty
           clothes"; "stands jam-packed with fans"; "a packed
           theater" [syn: jammed, jam-packed, packed]
    2: pressed together or compressed; "packed snow"

Moby Thesaurus II by Grady Ward, 1.0:

175 Moby Thesaurus words for "packed":
   SRO, aground, alive with, anchored, awash, bloated, blocked, bound,
   brimful, brimming, bristling, bulging, bursting, capacity, caught,
   chained, chock-full, choked, choked up, chuck-full, clogged,
   clogged up, close, close-knit, close-textured, close-woven,
   compact, compacted, compressed, concentrated, concrete, condensed,
   congested, consolidated, constipated, cooked, cooked-up, costive,
   cram-full, crammed, crammed full, crawling, crowded, crowding,
   cut out, cut-and-dried, cut-and-dry, dense, distended, doctored,
   drenched, engineered, farci, fast, fastened, filled,
   filled to overflowing, firm, fixed, flush, foul, fouled, full,
   full to bursting, gluey, glutted, gorged, groaning, grounded, hard,
   heavy, held, high and dry, hyperemic, impacted, impenetrable,
   impermeable, in profusion, in spate, in the bag, inextricable,
   infarcted, jam-packed, jammed, juggled, lavish, loaded,
   manipulated, massive, moored, nonporous, obstipated, obstructed,
   on ice, overblown, overburdened, overcharged, overfed, overflowing,
   overfraught, overfreighted, overfull, overladen, overloaded,
   overstocked, overstuffed, oversupplied, overweighted,
   packed like sardines, planned, plenary, plethoric, plotted,
   plugged, plugged up, populous, prearranged, preconcerted,
   precontrived, premeditated, preordered, prodigal, profuse,
   proliferating, prolific, put-up, ready to burst, replete, rife,
   rigged, round, running over, satiated, saturated, schemed, serried,
   set-up, soaked, solid, stacked, standing room only, stopped,
   stopped up, stranded, stuck, stuck fast, studded, stuffed,
   stuffed up, substantial, superabundant, supercharged,
   supersaturated, surcharged, surfeited, swarming, swollen, teeming,
   tethered, thick, thick as hail, thick with, thick-coming,
   thick-growing, thickset, thronged, thronging, tied, topful,
   transfixed, viscid, viscose, viscous, wedged, with