[1] : The Collaborative International Dictionary of English v.0.48

effusiveness \effu"siveness\ n.
   a friendly open trait of a talkative person; enthusiasm
   exhibited with little restraint.

   syn: expansiveness.
        wordnet 1.5 +pjc

[2] : The Collaborative International Dictionary of English v.0.48

effusive \effu"sive\, a.
   1. pouring out; pouring forth freely. archaic "washed with
      the effusive wave." --pope.
      1913 webster

   2. geol. formed by an outpouring of molten lava, or
      pertaining to rocks so formed.
      pjc

   3. overly demonstrative; expressing emotion in an
      unrestrained manner; exhibiting unrestrained enthusiasm;
      -- of people and human actions; as, effusive thanks; an
      effusive letter of recommendation. contrasted with
      reserved. wordnet sense 1+2

   syn: gushing, gushy, burbling, burbly. pjc

   effusive rocks geol., volcanic rocks formed by a
      nonexplosive outpouring of lava in molten or plastic form;
      in distinction from so-called intrusive, or plutonic,
      rocks. -- effu"sively, adv. -- effu"siveness, n.
      1913 webster
see also:
reserved effusive rocks intrusive plutonic effu"sively effu"siveness 

[3] : WordNet (r) 2.0

effusiveness
     n : a friendly open trait of a talkative person syn: expansiveness
see also:
expansiveness 

Effusiveness >> E Words
Effusiveness, definition of term: Effusiveness
effusiveness_pag1.html