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):

ennobling
    adj 1: investing with dignity or honor; "the dignifying effect
           of his presence"; "the ennobling influence of cultural
           surroundings" [syn: dignifying, ennobling]
    2: tending to exalt; "an exalting eulogy"; "ennobling thoughts"
       [syn: ennobling, exalting]