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]

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]

Moby Thesaurus II by Grady Ward, 1.0:

237 Moby Thesaurus words for "patent":
   OK, admission, aegis, allowance, apparent, arm, arm guard, armor,
   authorize, backstop, blank check, blatant, bless, bound, brevet,
   buffer, bulwark, bumper, carte blanche, certificate,
   certificate of invention, certify, champion, charter, clean-cut,
   clear, clear as crystal, clear-cut, cloak, compass about,
   concession, condition, confine, consent, conserve, conspicuous,
   contain, contraceptive, control, copyright, cover, crash helmet,
   crystal-clear, cushion, dashboard, defend, defined, definite,
   diploma, diplomatic immunity, discernible, discharge, discipline,
   dispensation, distinct, dodger, draw the line, empower, enable,
   enfranchise, ensure, entitle, evident, exception, exemption,
   explicit, express, face mask, favor, fence, fend, fender,
   finger guard, flagrant, foot guard, franchise, freedom, fuse,
   give official sanction, give power, glaring, goggles, governor,
   grant, gross, guarantee, guard, guardrail, hand guard, handrail,
   harbor, hard hat, haven, hedge about, helmet, immunity, in focus,
   indisputable, indubitable, indulgence, insulation, insure,
   interlock, keep, keep alive, keep from harm, keep intact,
   keep inviolate, keep safe, keep up, knee guard, knuckle guard,
   laminated glass, leave, legalize, legislative immunity, legitimize,
   letters patent, liberty, license, life preserver, lifeline,
   lightning conductor, lightning rod, limit, maintain, make safe,
   manifest, mask, moderate, mudguard, narrow, nestle, nose guard,
   not destroy, not endanger, not expend, not use up, not waste,
   noticeable, observable, obvious, okay, open-and-shut, pad, padding,
   palladium, palpable, perceivable, perceptible, permission,
   permission to enter, permit, perspicuous, physical, pilot, plain,
   plain as day, police, preserve, preventive, privilege, prominent,
   pronounced, prophylactic, protect, protective clothing,
   protective umbrella, qualify, rank, ratify, register,
   registered trademark, release, restrain, restrict,
   ride shotgun for, royal grant, safeguard, safety, safety glass,
   safety plug, safety rail, safety shoes, safety switch,
   safety valve, sanction, save, scant, screen, seat belt, secure,
   seeable, self-evident, self-explaining, self-explanatory,
   service mark, shelter, shield, shin guard, shroud, spare,
   special favor, special permission, specialize, staring, stint,
   straightforward, straiten, sun helmet, support, sustain, tangible,
   ticket, ticket of admission, to be seen, trade name, trademark,
   transparent, umbrella, unclosed, underwrite, unequivocal,
   unmistakable, unobstructed, uphold, validate, visible,
   vouchsafement, waiver, warrant, well-defined, well-marked,
   well-pronounced, well-resolved, windscreen, windshield