The Collaborative International Dictionary of English v.0.48:

Renaissance \Re*nais`sance"\ (F. re-n[asl]`s[aum]Ns"; E.
   r[-e]-n[=a]s"sans), n. [F., fr. rena[^i]tre to be born again.
   Cf. Renascence.]
   A new birth, or revival. Specifically:
   (a) The transitional movement in Europe, marked by the
       revival of classical learning and art in Italy in the
       15th century, and the similar revival following in other
       countries.
   (b) The style of art which prevailed at this epoch.
       [1913 Webster]

             The Renaissance was rather the last stage of the
             Middle Ages, emerging from ecclesiastical and
             feudal despotism, developing what was original in
             mediaeval ideas by the light of classic arts and
             letters.                             --J. A.
                                                  Symonds
                                                  (Encyc.
                                                  Brit.).
       [1913 Webster]

WordNet (r) 3.0 (2006):

Renaissance
    n 1: the period of European history at the close of the Middle
         Ages and the rise of the modern world; a cultural rebirth
         from the 14th through the middle of the 17th centuries
         [syn: Renaissance, Renascence]
    2: the revival of learning and culture [syn: rebirth,
       Renaissance, Renascence]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "renaissance":
   new birth, palingenesis, palingenesy, reanimation, rebirth,
   recrudescence, refreshment, regeneracy, regenerateness,
   regeneration, regenesis, rejuvenation, rejuvenescence, renascence,
   renewal, restoration, resumption, resurgence, resurrection,
   resuscitation, return, revival, revivescence, revivescency,
   revivification, second wind, second youth