The Collaborative International Dictionary of English v.0.48:

Glibness \Glib"ness\, n.
   The quality of being glib.
   [1913 Webster]

WordNet (r) 3.0 (2006):

glibness
    n 1: a kind of fluent easy superficiality; "the glibness of a
         high-pressure salesman" [syn: glibness, slickness]

Moby Thesaurus II by Grady Ward, 1.0:

69 Moby Thesaurus words for "glibness":
   articulateness, big mouth, blandness, butter, candor,
   command of language, command of words, communicativeness,
   conversableness, effective style, effusion, effusiveness,
   eloquence, eloquent tongue, expression, expressiveness, facundity,
   fair words, felicitousness, felicity, flow of words,
   flowing tongue, fluency, fluent tongue, flux de bouche,
   flux de paroles, flux of words, frankness, fulsomeness, garrulity,
   garrulousness, gassiness, gift of expression, gift of gab,
   graphicness, gregariousness, gush, gushiness, honeyed words,
   incense, long-windedness, loose tongue, loquaciousness, loquacity,
   meaningfulness, oiliness, openness, oratory, prolixity, rhetoric,
   silver tongue, slickness, slush, smoothness, smugness, sociability,
   soft soap, soft words, spate of words, suaveness, suavity,
   sweet talk, sweet words, talkativeness, unctuousness, verbosity,
   vividness, volubility, windiness