The Collaborative International Dictionary of English v.0.48:

Patent \Pat"ent\ (p[a^]t"ent or p[=a]t"ent), a. [L. patens,
   -entis, p. pr. of patere to be open: cf. F. patent. Cf.
   Fathom.]
   1.

   Note: (Oftener pronounced p[=a]t"ent in this sense) Open;
         expanded; evident; apparent; unconcealed; manifest;
         public; conspicuous.
         [1913 Webster]

               He had received instructions, both patent and
               secret.                            --Motley.
         [1913 Webster]

   2. Open to public perusal; -- said of a document conferring
      some right or privilege; as, letters patent. See Letters
      patent, under 3d Letter.
      [1913 Webster]

   3. Appropriated or protected by letters patent; secured by
      official authority to the exclusive possession, control,
      and disposal of some person or party; patented; as, a
      patent right; patent medicines.
      [1913 Webster]

            Madder . . . in King Charles the First's time, was
            made a patent commodity.              --Mortimer.
      [1913 Webster]

   4. (Bot.) Spreading; forming a nearly right angle with the
      steam or branch; as, a patent leaf.
      [1913 Webster]

   Patent leather, a varnished or lacquered leather, used for
      boots and shoes, and in carriage and harness work.

   Patent office, a government bureau for the examination of
      inventions and the granting of patents.

   Patent right.
      (a) The exclusive right to an invention, and the control
          of its manufacture.
      (b) (Law) The right, granted by the sovereign, of
          exclusive control of some business of manufacture, or
          of the sale of certain articles, or of certain offices
          or prerogatives.

   Patent rolls, the registers, or records, of patents.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Patent \Pat"ent\, n. [Cf. F. patente. See Patent, a.]
   1. A letter patent, or letters patent; an official document,
      issued by a sovereign power, conferring a right or
      privilege on some person or party. Specifically:
      (a) A writing securing to an invention.
      (b) A document making a grant and conveyance of public
          lands.
          [1913 Webster]

                Four other gentlemen of quality remained
                mentioned in that patent.         --Fuller.
          [1913 Webster]

   Note: In the United States, by the act of 1870, patents for
         inventions are issued for seventeen years, without the
         privilege of renewal except by act of Congress.
         [1913 Webster]

   2. The right or privilege conferred by such a document;
      hence, figuratively, a right, privilege, or license of the
      nature of a patent.
      [1913 Webster]

            If you are so fond over her iniquity, give her
            patent to offend.                     --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Patent \Pat"ent\, v. t. [imp. & p. p. Patented; p. pr. & vb.
   n. Patenting.]
   To grant by patent; to make the subject of a patent; to
   secure or protect by patent; as, to patent an invention; to
   patent public lands.
   [1913 Webster]

WordNet (r) 3.0 (2006):

patent
    adj 1: (of a bodily tube or passageway) open; affording free
           passage; "patent ductus arteriosus"
    2: clearly revealed to the mind or the senses or judgment; "the
       effects of the drought are apparent to anyone who sees the
       parched fields"; "evident hostility"; "manifest disapproval";
       "patent advantages"; "made his meaning plain"; "it is plain
       that he is no reactionary"; "in plain view" [syn: apparent,
       evident, manifest, patent, plain, unmistakable]
    n 1: a document granting an inventor sole rights to an invention
         [syn: patent, patent of invention]
    2: an official document granting a right or privilege [syn:
       patent, letters patent]
    v 1: obtain a patent for; "Should I patent this invention?"
    2: grant rights to; grant a patent for
    3: make open to sight or notice; "His behavior has patented an
       embarrassing fact about him"