The Collaborative International Dictionary of English v.0.48:

Public \Pub"lic\, a. [L. publicus, poblicus, fr. populus people:
   cf. F. public. See People.]
   1. Of or pertaining to the people; belonging to the people;
      relating to, or affecting, a nation, state, or community;
      -- opposed to private; as, the public treasury.
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            To the public good
            Private respects must yield.          --Milton.
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            He [Alexander Hamilton] touched the dead corpse of
            the public credit, and it sprung upon its feet. --D.
                                                  Webster.
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   2. Open to the knowledge or view of all; general; common;
      notorious; as, public report; public scandal.
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            Joseph, . . . not willing to make her a public
            example, was minded to put her away privily. --Matt.
                                                  i. 19.
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   3. Open to common or general use; as, a public road; a public
      house. "The public street." --Shak.
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   public act or public statute (Law), an act or statute
      affecting matters of public concern. Of such statutes the
      courts take judicial notice.

   Public credit. See under Credit.

   Public funds. See Fund, 3.

   Public house, an inn, or house of entertainment.

   Public law.
      (a) See International law, under International.
      (b) A public act or statute.

   Public nuisance. (Law) See under Nuisance.

   Public orator. (Eng. Universities) See Orator, 3.

   Public stores, military and naval stores, equipments, etc.


   Public works, all fixed works built by civil engineers for
      public use, as railways, docks, canals, etc.; but
      strictly, military and civil engineering works constructed
      at the public cost.
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WordNet (r) 3.0 (2006):

public law
    n 1: a law affecting the public at large