The Collaborative International Dictionary of English v.0.48:

Felicitous \Fe*lic"i*tous\, a.
   Characterized by felicity; happy; prosperous; delightful;
   skillful; successful; happily applied or expressed;
   appropriate.
   [1913 Webster]

         Felicitous words and images.             --M. Arnold.
   -- Fe*lic"i*tous*ly, adv. -- Fe*lic"i*tous*ness, n.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

felicitousness \fe*lic"i*tous*ness\ n.
   a pleasing and appropriate manner or style, especially of
   expression.

   Syn: felicity.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

felicitousness
    n 1: pleasing and appropriate manner or style (especially manner
         or style of expression) [syn: felicity, felicitousness]
         [ant: infelicity]