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]

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]

Moby Thesaurus II by Grady Ward, 1.0:

187 Moby Thesaurus words for "license":
   Lehrfreiheit, OK, academic freedom, accredit, admission, agency,
   agentship, allow, allowance, anarchy, approve, assign, assignment,
   assumption, authority, authorization, authorize, blank check,
   brevet, building permit, care, carte blanche, certificate, certify,
   chaos, charge, charter, commission, commissioning, commit,
   commitment, confusion, consent, consign, consignment,
   constitutional freedom, copyright, cure, debauchery, debauchment,
   delegate, delegated authority, delegation, deputation, depute,
   deputize, detach, detail, devolute, devolution, devolve,
   devolve upon, devolvement, diplomatic immunity, discharge,
   disobedience, dispensation, dissipation, dissoluteness, document,
   embassy, empower, empowerment, enable, enfranchise, entitle,
   entrust, entrusting, entrustment, errand, exception, executorship,
   exemption, exequatur, fabulous formless darkness, factorship,
   familiarity, fastness, favor, fishing license, foul-up, franchise,
   freedom, freedom from fear, freedom from want, freedom of worship,
   full power, gallantry, give in charge, give official sanction,
   give power, grant, hassle, hubris, hunting license, immunity,
   imposition, imprimatur, indiscipline, indulgence, insubordination,
   interregnum, irresponsibility, jurisdiction, lawlessness, laxity,
   leave, legalize, legation, legislative immunity, legitimize, let,
   liberties, libertinage, libertinism, liberty, liberty abused,
   licentiousness, lieutenancy, loose, looseness, mandate, misrule,
   mission, mix-up, morass, muddle, mutiny, nihil obstat, office,
   okay, patent, permission, permission to enter, permit,
   plenipotentiary power, post, power of attorney, power to act,
   power vacuum, presumption, presumptuousness, privilege,
   procuration, profligacy, proxy, purview, rakishness, rampant will,
   ratify, regency, regentship, relaxation, release, responsibility,
   run, sanction, screw-up, send out, slackness, snafu, special favor,
   special permission, suffer, task, the Four Freedoms, the run of,
   ticket, ticket of admission, transfer, trust, trusteeship,
   unaccountability, unbridledness, uncontrol, undue liberty,
   unrestraint, validate, venery, vicarious authority, vouchsafement,
   waiver, warrant, wenching, whoring, wildness, willfulness