The Collaborative International Dictionary of English v.0.48:

Renew \Re*new"\, v. i.
   To become new, or as new; to grow or begin again.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Renew \Re*new"\ (r?-n?"), v. t. [imp. & p. p. Reneved (-n?d");
   p. pr. & vb. n. Renewing.] [Pref. re- + new. Cf.
   Renovate.]
   1. To make new again; to restore to freshness, perfection, or
      vigor; to give new life to; to rejuvenate; to
      re["e]stablish; to recreate; to rebuild.
      [1913 Webster]

            In such a night
            Medea gathered the enchanted herbs
            That did renew old Aeson.             --Shak.
      [1913 Webster]

   2. Specifically, to substitute for (an old obligation or
      right) a new one of the same nature; to continue in force;
      to make again; as, to renew a lease, note, or patent.
      [1913 Webster]

   3. To begin again; to recommence.
      [1913 Webster]

            The last great age . . . renews its finished course.
                                                  --Dryden.
      [1913 Webster]

   4. To repeat; to go over again.
      [1913 Webster]

            The birds-their notes renew.          --Milton.
      [1913 Webster]

   5. (Theol.) To make new spiritually; to regenerate.
      [1913 Webster]

            Be ye transformed by the renewing of your mind.
                                                  --Rom. xii. 2.
      [1913 Webster]

WordNet (r) 3.0 (2006):

renew
    v 1: reestablish on a new, usually improved, basis or make new
         or like new; "We renewed our friendship after a hiatus of
         twenty years"; "They renewed their membership" [syn:
         regenerate, renew]
    2: cause to appear in a new form; "the old product was
       reincarnated to appeal to a younger market" [syn:
       reincarnate, renew]

Moby Thesaurus II by Grady Ward, 1.0:

185 Moby Thesaurus words for "renew":
   accommodate, adapt, adjust, alter, ameliorate, amend, animate,
   begin again, better, brace, brace up, break up, bring back,
   bring to, brisk, brisken, buck up, call back, change, cheer,
   chirk up, coin, come again, confirm, continue, convert, copy,
   correct, deform, denature, ditto, diversify, do a repeat, do again,
   do over, double, duplicate, echo, enliven, exhilarate, face-lift,
   fillip, fit, fortify, fresh up, freshen, freshen up, furbish,
   galvanize, go back to, have another shot, have another try,
   imitate, improve, inaugurate, infuse life into, ingeminate,
   innovate, invent, invigorate, iterate, jazz up, make over,
   meliorate, mend, mint, mitigate, modernize, modify, modulate,
   mutate, neologize, neoterize, new-model, overhaul, overthrow,
   parrot, perk up, pick up, pique, plagiarize, provoke, qualify,
   quicken, quote, re-create, re-form, reactivate, reaffirm, realign,
   reanimate, reassert, rebegin, rebuild, recall, recall to life,
   recharge, reclaim, recommence, recondition, reconstruct, recreate,
   recruit, rectify, redecorate, redeem, redesign, redo, redouble,
   reduplicate, reecho, reenter, reestablish, refashion, refit,
   reform, refresh, refreshen, refurbish, regale, regenerate,
   regurgitate, rehabilitate, reheat the ashes, reincarnate,
   reinspire, reinstate, reinvigorate, reiterate, rejuvenate,
   rekindle, relight, remake, remodel, renovate, reopen, repair,
   repeat, replace, replenish, reprise, reproduce, resay, reshape,
   restate, restore, restore self-respect, restructure, resume,
   resurrect, resuscitate, retrieve, return to, revamp, revise,
   revitalize, revive, revivify, rewarm, ring the changes, say again,
   set straight, set up, sharpen, shift the scene, shuffle the cards,
   start all over, stimulate, stir the embers, subvert, take up,
   take up again, transform, turn the scale, turn the tables,
   turn the tide, turn upside down, update, vary, vivify, warm over,
   warm up, whet, work a change, worsen