[syn: suavity, suaveness, blandness, smoothness]
4.  the quality of having a level and even surface; 
- Example: "the water was a glassy smoothness"
- Example: "the weather system of the Pacific is determined by the uninterrupted smoothness of the ocean"
5.  the quality of being free from errors or interruptions; 
- Example: "the five-speed manual gearbox is smoothness personified"
The Collaborative International Dictionary of English v.0.48:
Smoothness \Smooth"ness\, n.
   Quality or state of being smooth.
   [1913 Webster]
WordNet (r) 3.0 (2006):
smoothness
    n 1: a texture without roughness; smooth to the touch; "admiring
         the slim smoothness of her thighs"; "some artists prefer
         the smoothness of a board" [ant: raggedness, roughness]
    2: powerful and effective language; "his eloquence attracted a
       large congregation"; "fluency in spoken and written English
       is essential"; "his oily smoothness concealed his guilt from
       the police" [syn: eloquence, fluency, smoothness]
    3: the quality of being bland and gracious or ingratiating in
       manner [syn: suavity, suaveness, blandness,
       smoothness]
    4: the quality of having a level and even surface; "the water
       was a glassy smoothness"; "the weather system of the Pacific
       is determined by the uninterrupted smoothness of the ocean"
    5: the quality of being free from errors or interruptions; "the
       five-speed manual gearbox is smoothness personified"