The Collaborative International Dictionary of English v.0.48:

Flippancy \Flip"pan*cy\, n.[See Flippant.]
   The state or quality of being flippant.
   [1913 Webster]

         This flippancy of language.              --Bp. Hurd.
   [1913 Webster]

WordNet (r) 3.0 (2006):

flippancy
    n 1: inappropriate levity; "her mood changed and she was all
         lightness and joy" [syn: flippancy, light-mindedness]

Moby Thesaurus II by Grady Ward, 1.0:

106 Moby Thesaurus words for "flippancy":
   absentmindedness, banter, booing, brashness, brassiness,
   brazenfacedness, brazenness, carelessness, catcalling, chaffing,
   cheek, cheekiness, cockiness, contempt, derision, discourtesy,
   disregard, disregardfulness, disrespect, disrespectfulness,
   distraction, face of brass, facetiousness, fleering, flightiness,
   fooling, freshness, frivolity, frivolousness, giddiness, grinning,
   heedlessness, hissing, hooting, impertinence, impishness,
   impudence, inadvertence, inadvertency, inattention,
   inattentiveness, inconsideration, incuriosity, indifference,
   inobservance, insolence, irreverence, jeering, jocularity, joshing,
   leering, levity, lightmindedness, lip, merriment, mischievousness,
   mockery, mouth, negligence, nonobservance, obliviousness,
   offhandedness, panning, pertness, playfulness, prankishness,
   pranksomeness, ragging, raillery, rallying, razzing,
   regardlessness, ridicule, roasting, roguishness, rudeness,
   sauciness, scoffing, shallowness, side, smart-aleckiness,
   smartness, smirking, sneering, snickering, sniggering, snorting,
   sportiveness, superficiality, taunting, thoughtlessness, trickery,
   trickiness, twitting, unalertness, unawareness, unconsciousness,
   unheedfulness, unintentiveness, unmindfulness, unobservance,
   unwariness, unwatchfulness, volatility, waggery, waggishness