The Collaborative International Dictionary of English v.0.48:

Suavity \Suav"i*ty\, n. [L. suavitas: cf. F. suavit['e].]
   1. Sweetness to the taste. [Obs.] --Sir T. Browne.
      [1913 Webster]

   2. The quality of being sweet or pleasing to the mind;
      agreeableness; softness; pleasantness; gentleness;
      urbanity; as, suavity of manners; suavity of language,
      conversation, or address. --Glanvill.
      [1913 Webster]

WordNet (r) 3.0 (2006):

suavity
    n 1: the quality of being bland and gracious or ingratiating in
         manner [syn: suavity, suaveness, blandness,
         smoothness]