The Collaborative International Dictionary of English v.0.48:

Magnificence \Mag*nif"i*cence\, n. [F. magnificence, L.
   magnificentia. See Magnific.]
   The act of doing what is magnificent; the state or quality of
   being magnificent. --Acts xix. 27. "Then cometh
   magnificence." --Chaucer.
   [1913 Webster]

         And, for the heaven's wide circuit, let it speak
         The Maker's high magnificence, who built
         so spacious.                             --Milton.
   [1913 Webster]

         The noblest monuments of Roman magnificence. --Eustace.
   [1913 Webster]

WordNet (r) 3.0 (2006):

magnificence
    n 1: splendid or imposing in size or appearance; "the grandness
         of the architecture"; "impressed by the richness of the
         flora" [syn: impressiveness, grandness, magnificence,
         richness]
    2: the quality of being magnificent or splendid or grand; "for
       magnificence and personal service there is the Queen's
       hotel"; "his `Hamlet' lacks the brilliance that one expects";
       "it is the university that gives the scene its stately
       splendor"; "an imaginative mix of old-fashioned grandeur and
       colorful art"; "advertisers capitalize on the grandness and
       elegance it brings to their products" [syn: magnificence,
       brilliance, splendor, splendour, grandeur,
       grandness]