The Collaborative International Dictionary of English v.0.48:

dignify \dig"ni*fy\, v. t. [imp. & p. p. Dignified; p. pr. &
   vb. n. Dignifying.] [OF. dignifier, fr. LL. dignificare; L.
   dignus worthy + ficare (in comp.), facere to make. See
   Deign, and Fact.]
   To invest with dignity or honor; to make illustrious; to give
   distinction to; to exalt in rank; to honor.
   [1913 Webster]

         Your worth will dignify our feast.       --B. Jonson.

   Syn: To exalt; elevate; prefer; advance; honor; illustrate;
        adorn; ennoble.
        [1913 Webster]

WordNet (r) 3.0 (2006):

dignify
    v 1: confer dignity or honor upon; "He was dignified with a
         title" [syn: ennoble, dignify]
    2: raise the status of; "I shall not dignify this insensitive
       remark with an answer"