The Collaborative International Dictionary of English v.0.48:

Discard \Dis*card"\, v. t. [imp. & p. p. Discarded; p. pr. &
   vb. n. Discarding.]
   1. (Card Playing) To throw out of one's hand, as superfluous
      cards; to lay aside (a card or cards).
      [1913 Webster]

   2. To cast off as useless or as no longer of service; to
      dismiss from employment, confidence, or favor; to
      discharge; to turn away.
      [1913 Webster]

            They blame the favorites, and think it nothing
            extraordinary that the queen should . . . resolve to
            discard them.                         --Swift.
      [1913 Webster]

   3. To put or thrust away; to reject.
      [1913 Webster]

            A man discards the follies of boyhood. --I. Taylor.

   Syn: To dismiss; displace; discharge; cashier.
        [1913 Webster]

WordNet (r) 3.0 (2006):

discarded
    adj 1: thrown away; "wearing someone's cast-off clothes";
           "throwaway children living on the streets"; "salvaged
           some thrown-away furniture" [syn: cast-off(a),
           discarded, throwaway(a), thrown-away(a)]

Moby Thesaurus II by Grady Ward, 1.0:

52 Moby Thesaurus words for "discarded":
   abandoned, belied, cast-off, castaway, confounded, confuted,
   contemned, declined, declined with thanks, deflated, denied,
   derelict, deserted, despised, disapproved, discounted, discredited,
   disdained, dismissed, disowned, disproved, disputed, disused,
   excepted, excluded, exploded, exposed, forsaken, forsworn, ignored,
   impugned, invalidated, jettisoned, left, marooned, negated,
   negatived, not considered, overthrown, overturned, punctured,
   rebuffed, refused, refuted, rejected, renounced, repudiated,
   repulsed, scouted, shown up, spurned, upset