The Collaborative International Dictionary of English v.0.48:

Prolixity \Pro*lix"i*ty\, n. [L. prolixitas: cf. F.
   prolixit['e].]
   The quality or state of being prolix; great length; minute
   detail; as, prolixity in discourses and writings. "For
   fulsomeness of his prolixitee." --Chaucer.
   [1913 Webster]

         Idly running on with vain prolixity.     --Drayton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

prolixity
    n 1: boring verbosity [syn: prolixity, prolixness,
         windiness, long-windedness, wordiness]

Moby Thesaurus II by Grady Ward, 1.0:

79 Moby Thesaurus words for "prolixity":
   bedizenment, big mouth, boringness, candor, cloud of words,
   communicativeness, conversableness, dullness, duplication,
   duplication of effort, effusion, effusiveness, embellishment,
   expletive, extravagance, fat, featherbedding, filling,
   flow of words, flowing tongue, fluency, fluent tongue,
   flux de bouche, flux de paroles, flux of words, frankness, frill,
   frills, frippery, garrulity, garrulousness, gassiness, gift of gab,
   gingerbread, glibness, gregariousness, gush, gushiness,
   humdrumminess, humdrumness, irksomeness, logorrhea,
   long-windedness, longiloquence, loose tongue, loquaciousness,
   loquacity, luxury, monotonousness, needlessness, openness,
   ornamentation, overadornment, overlap, padding, payroll padding,
   pleonasm, redundance, redundancy, slush, sociability,
   spate of words, superfluity, superfluousness, talkativeness,
   tautology, tediousness, tiresomeness, unnecessariness, verbalism,
   verbality, verbiage, verboseness, verbosity, volubility,
   wearifulness, wearisomeness, windiness, wordiness