The Collaborative International Dictionary of English v.0.48:

License \Li"cense\ (l[imac]"sens), v. t. [imp. & p. p.
   Licensed (l[imac]"senst); p. pr. & vb. n. Licensing.]
   To permit or authorize by license; to give license to; as, to
   license a man to preach. --Milton. --Shak.

   Syn: licence, certify. [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

License \Li"cense\ (l[imac]"sens), n. [Written also licence.]
   [F. licence, L. licentia, fr. licere to be permitted, prob.
   orig., to be left free to one; akin to linquere to leave. See
   Loan, and cf. Illicit, Leisure.]
   1. Authority or liberty given to do or forbear any act;
      especially, a formal permission from the proper
      authorities to perform certain acts or to carry on a
      certain business, which without such permission would be
      illegal; a grant of permission; as, a license to preach,
      to practice medicine, to sell gunpowder or intoxicating
      liquors.
      [1913 Webster]

            To have a license and a leave at London to dwell.
                                                  --P. Plowman.
      [1913 Webster]

   2. The document granting such permission. --Addison.
      [1913 Webster]

   3. Excess of liberty; freedom abused, or used in contempt of
      law or decorum; disregard of law or propriety.
      [1913 Webster]

            License they mean when they cry liberty. --Milton.
      [1913 Webster]

   4. That deviation from strict fact, form, or rule, in which
      an artist or writer indulges, assuming that it will be
      permitted for the sake of the advantage or effect gained;
      as, poetic license; grammatical license, etc.
      [1913 Webster]

   Syn: Leave; liberty; permission.
        [1913 Webster]

WordNet (r) 3.0 (2006):

license
    n 1: a legal document giving official permission to do something
         [syn: license, licence, permit]
    2: freedom to deviate deliberately from normally applicable
       rules or practices (especially in behavior or speech) [syn:
       license, licence]
    3: excessive freedom; lack of due restraint; "when liberty
       becomes license dictatorship is near"- Will Durant; "the
       intolerable license with which the newspapers break...the
       rules of decorum"- Edmund Burke [syn: license, licence]
    4: the act of giving a formal (usually written) authorization
       [syn: license, permission, permit]
    v 1: authorize officially; "I am licensed to practice law in
         this state" [syn: license, licence, certify] [ant:
         decertify, derecognise, derecognize]