WordNet (r) 3.0 (2006):

jazz up
    v 1: make more interesting or lively; "juice up a party"; "pep
         up your paper" [syn: jazz up, juice up, pep up,
         ginger up]

Moby Thesaurus II by Grady Ward, 1.0:

61 Moby Thesaurus words for "jazz up":
   accelerate, aggravate, animate, arouse, beef up, blow up,
   complicate, concentrate, condense, consolidate, deepen, double,
   dynamize, electrify, energize, enhance, enliven, exacerbate,
   exaggerate, exhilarate, fillip, fire, galvanize, hearten, heat up,
   heighten, hop up, hot up, inflame, infuse life into, intensify,
   invigorate, key up, kindle, liven, magnify, make complex, pep up,
   perk up, pick up, pique, provoke, quicken, ramify, redouble,
   reinforce, renew, resuscitate, revive, rouse, sharpen, snap up,
   soup up, step up, stimulate, strengthen, triple, vitalize, warm,
   whet, zip up