The Collaborative International Dictionary of English v.0.48:

Liberty \Lib"er*ty\ (l[i^]b"[~e]r*t[y^]), n.; pl. Liberties
   (-t[i^]z). [OE. liberte, F. libert['e], fr. L. libertas, fr.
   liber free. See Liberal.]
   1. The state of a free person; exemption from subjection to
      the will of another claiming ownership of the person or
      services; freedom; -- opposed to slavery, serfdom,
      bondage, or subjection.
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            But ye . . . caused every man his servant, and every
            man his handmaid whom he had set at liberty at their
            pleasure, to return, and brought them into
            subjection.                           --Jer. xxxiv.
                                                  16.
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            Delivered fro the bondage of corruption into the
            glorious liberty of the sons of God.  --Bible, 1551.
                                                  Rom. viii. 21.
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   2. Freedom from imprisonment, bonds, or other restraint upon
      locomotion.
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            Being pent from liberty, as I am now. --Shak.
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   3. A privilege conferred by a superior power; permission
      granted; leave; as, liberty given to a child to play, or
      to a witness to leave a court, and the like.
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   4. Privilege; exemption; franchise; immunity enjoyed by
      prescription or by grant; as, the liberties of the
      commercial cities of Europe.
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            His majesty gave not an entire county to any; much
            less did he grant . . . any extraordinary liberties.
                                                  --Sir J.
                                                  Davies.
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   5. The place within which certain immunities are enjoyed, or
      jurisdiction is exercised. [Eng.]
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            Brought forth into some public or open place within
            the liberty of the city, and there . . . burned.
                                                  --Fuller.
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   6. A certain amount of freedom; permission to go freely
      within certain limits; also, the place or limits within
      which such freedom is exercised; as, the liberties of a
      prison.
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   7. A privilege or license in violation of the laws of
      etiquette or propriety; as, to permit, or take, a liberty.
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            He was repeatedly provoked into striking those who
            had taken liberties with him.         --Macaulay.
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   8. The power of choice; freedom from necessity; freedom from
      compulsion or constraint in willing.
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            The idea of liberty is the idea of a power in any
            agent to do or forbear any particular action,
            according to the determination or thought of the
            mind, whereby either of them is preferred to the
            other.                                --Locke.
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            This liberty of judgment did not of necessity lead
            to lawlessness.                       --J. A.
                                                  Symonds.
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   9. (Manege) A curve or arch in a bit to afford room for the
      tongue of the horse.
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   10. (Naut.) Leave of absence; permission to go on shore.
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   At liberty.
       (a) Unconfined; free.
       (b) At leisure.

   Civil liberty, exemption from arbitrary interference with
      person, opinion, or property, on the part of the
      government under which one lives, and freedom to take part
      in modifying that government or its laws.

   Liberty bell. See under Bell.

   Liberty cap.
       (a) The Roman pileus which was given to a slave at his
           manumission.
       (b) A limp, close-fitting cap with which the head of
           representations of the goddess of liberty is often
           decked. It is sometimes represented on a spear or a
           liberty pole.

   Liberty of the press, freedom to print and publish without
      official supervision.

   Liberty party, the party, in the American Revolution, which
      favored independence of England; in more recent usage, a
      party which favored the emancipation of the slaves.

   Liberty pole, a tall flagstaff planted in the ground, often
      surmounted by a liberty cap. [U. S.]

   Moral liberty, that liberty of choice which is essential to
      moral responsibility.

   Religious liberty, freedom of religious opinion and
      worship.
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   Syn: Leave; permission; license.

   Usage: Liberty, Freedom. These words, though often
          interchanged, are distinct in some of their
          applications. Liberty has reference to previous
          restraint; freedom, to the simple, unrepressed
          exercise of our powers. A slave is set at liberty; his
          master had always been in a state of freedom. A
          prisoner under trial may ask liberty (exemption from
          restraint) to speak his sentiments with freedom (the
          spontaneous and bold utterance of his feelings). The
          liberty of the press is our great security for freedom
          of thought.
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Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "at liberty":
   afoot and lighthearted, at large, available, clear, detached,
   disengaged, easygoing, emancipated, fallow, footloose,
   footloose and fancy-free, free, free and easy, free as air,
   freeborn, freed, go-as-you-please, idle, in the clear, jobless,
   leisure, leisured, liberated, loose, lumpen, off, off duty,
   off work, on the loose, otiose, out of employ, out of harness,
   out of work, released, scot-free, unattached, uncommitted,
   unemployable, unemployed, unengaged, uninvolved, unoccupied