The Collaborative International Dictionary of English v.0.48:

Concinnity \Con*cin"ni*ty\, n. [L. concinnitas, fr. concinnus
   skillfully put together, beautiful. Of uncertain origin.]
   Internal harmony or fitness; mutual adaptation of parts;
   elegance; -- used chiefly of style of discourse. [R.]
   [1913 Webster]

         An exact concinnity and eveness of fancy. --Howell.
   [1913 Webster]