The Collaborative International Dictionary of English v.0.48:

Relinquish \Re*lin"quish\ (-kw?sh), v. t. [imp. & p. p.
   Relinquished (-kw?sht); p. pr. & vb. n. Relinquishing.]
   [OF. relinquir, L. relinquere to leave behind; pref. re- re +
   linquere to leave. See Loan, and cf. Relic, Relict.]
   [1913 Webster]
   1. To withdraw from; to leave behind; to desist from; to
      abandon; to quit; as, to relinquish a pursuit.
      [1913 Webster]

            We ought to relinquish such rites.    --Hooker.
      [1913 Webster]

            They placed Irish tenants upon the lands
            relinquished by the English.          --Sir J.
                                                  Davies.
      [1913 Webster]

   2. To give up; to renounce a claim to; resign; as, to
      relinquish a debt.
      [1913 Webster]

   Syn: To resign; leave; quit; forsake; abandon; desert;
        renounce; forb?ar; forego. See Resign.
        [1913 Webster]

WordNet (r) 3.0 (2006):

relinquished
    adj 1: that has been withdrawn or retreated from

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "relinquished":
   abandoned, abjured, antiquated, antique, archaic, ceded, deserted,
   discontinued, dispensed with, disposed of, disused, done with,
   forgone, forsworn, not worth saving, obsolescent, obsolete, old,
   old-fashioned, on the shelf, out, out of use, out-of-date,
   outdated, outmoded, outworn, past use, pensioned off, recanted,
   released, renounced, resigned, retired, retracted, sacrificed,
   superannuate, superannuated, superseded, surrendered, waived,
   worn-out, yielded