Source : Webster's Revised Unabridged Dictionary (1913)

Derelict \Der"e*lict\, a. [L. derelictus, p. p. of derelinquere
   to forsake wholly, to abandon; de- + relinquere to leave. See
   {Relinquish}.]
   1. Given up or forsaken by the natural owner or guardian;
      left and abandoned; as, derelict lands.

            The affections which these exposed or derelict
            children bear to their mothers, have no grounds of
            nature or assiduity but civility and opinion. --Jer.
      Taylor.

   2. Lost; adrift; hence, wanting; careless; neglectful;
      unfaithful.

            They easily prevailed, so as to seize upon the
            vacant, unoccupied, and derelict minds of his
            [Chatham's] friends; and instantly they turned the
            vessel wholly out of the course of his policy.
                                                  --Burke.

            A government which is either unable or unwilling to
            redress such wrongs is derelict to its highest
            duties.                               --J. Buchanan.

Derelict \Der"e*lict\, n. (Law)
      (a) A thing voluntary abandoned or willfully cast away by
          its proper owner, especially a ship abandoned at sea.
      (b) A tract of land left dry by the sea, and fit for
          cultivation or use.

Source : WordNet®

derelict
     adj 1: deserted or abandoned as by an owner; "a derelict ship"
     2: failing in what duty requires; "derelict (or delinquent) in
        his duty"; "neglectful of his duties"; "remiss of you not
        to pay your bills" [syn: {delinquent}, {neglectful}, {remiss}]

derelict
     n 1: a person unable to support himself
     2: a ship abandoned on the high seas [syn: {abandoned ship}]