The Collaborative International Dictionary of English v.0.48:

Ennoble \En*no"ble\, v. t. [imp. & p. p. Ennobled; p. pr. &
   vb. n. Ennobling.] [Pref. en- + noble: cf. F. ennoblir.]
   1. To make noble; to elevate in degree, qualities, or
      excellence; to dignify. "Ennobling all that he touches."
      --Trench.
      [1913 Webster]

            What can ennoble sots, or slaves, or cowards?
            Alas! not all the blood of all the Howards. --Pope.
      [1913 Webster]

   2. To raise to the rank of nobility; as, to ennoble a
      commoner.

   Syn: To raise; dignify; exalt; elevate; aggrandize.
        [1913 Webster]

WordNet (r) 3.0 (2006):

ennoble
    v 1: confer dignity or honor upon; "He was dignified with a
         title" [syn: ennoble, dignify]
    2: give a title to someone; make someone a member of the
       nobility [syn: ennoble, gentle, entitle]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "ennoble":
   advance, aggrandize, apotheose, apotheosize, beatify, canonize,
   crown, deify, dignify, distinguish, elevate, enshrine, enthrone,
   erect, exalt, glamorize, glorify, graduate, honor, immortalize,
   kick upstairs, knight, lionize, magnify, make legendary, pass,
   prefer, promote, raise, saint, sanctify, set up, sublime, throne,
   up, upgrade, uplift, uprear