The Collaborative International Dictionary of English v.0.48:

Custody \Cus"to*dy\ (k?s"t?-d?), n. [L. custodia, fr. custos
   guard; prob. akin to Gr. ?????? to hide, and E. hide. Seee
   Hide to cover.]
   1. A keeping or guarding; care, watch, inspection, for
      keeping, preservation, or security.
      [1913 Webster]

            A fleet of thirty ships for the custody of the
            narrow seas.                          --Bacon.
      [1913 Webster]

   2. Judicial or penal safe-keeping.
      [1913 Webster]

            Jailer, take him to thy custody.      --Shak.
      [1913 Webster]

   3. State of being guarded and watched to prevent escape;
      restraint of liberty; confinement; imprisonment.
      [1913 Webster]

            What pease will be given
            To us enslaved, but custody severe,
            And stripes and arbitrary punishment? --Milton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

custody
    n 1: a state of being confined (usually for a short time); "his
         detention was politically motivated"; "the prisoner is on
         hold"; "he is in the custody of police" [syn: detention,
         detainment, hold, custody]
    2: holding by the police; "the suspect is in custody"
    3: (with `in') guardianship over; in divorce cases it is the
       right to house and care for and discipline a child; "my fate
       is in your hands"; "too much power in the president's hands";
       "your guests are now in my custody"; "the mother was awarded
       custody of the children" [syn: hands, custody]

Moby Thesaurus II by Grady Ward, 1.0:

94 Moby Thesaurus words for "custody":
   administration, auspices, captainship, care, chairmanship, charge,
   cold storage, confinement, conservation, convenership, cure,
   custodianship, dead storage, detention, dictatorship, directorate,
   directorship, dry storage, eagle eye, foremanship, generalship,
   governance, government, governorship, guard, guardedness,
   guardianship, guarding, guidance, hands, headship, hold,
   imprisonment, incarceration, intendancy, invigilation,
   jurisdiction, keep, keeping, leadership, lookout, management,
   managership, mastership, ministry, monitoring, observance,
   overseership, oversight, pastorage, pastorate, pastorship,
   patronage, peeled eye, preservation, presidency,
   preventive custody, proctoring, proctorship, protection,
   protective custody, protectorship, prudence, qui vive, safe hands,
   safekeeping, sharp eye, shelf-room, sovereignty, stewardship,
   storage, storage space, stowage, superintendence, superintendency,
   supervision, supervisorship, surveillance, trust, tutelage, vigil,
   vigilance, ward, wardenship, wardship, warehousing, wariness,
   watch, watch and ward, watchful eye, watchfulness, watching,
   weather eye, wing



Bouvier's Law Dictionary, Revised 6th Ed (1856):

CUSTODY. The detainer of a person by virtue of a lawful authority. To be in
custody, is to be lawfully detained under arrest. Vide 14 Vin. Ab. 359; 3
Chit. Pr. 355. In another sense, custody signifies having the care and
possession of a thing; as, the chancellor is entitled to the custody as the
keeper of the seal.