The Collaborative International Dictionary of English v.0.48:

Triviality \Triv`i*al"i*ty\, n.; pl. Trivialities. [Cf. F.
   trivialit['e]]
   1. The quality or state of being trivial; trivialness.
      [1913 Webster]

   2. That which is trivial; a trifle.
      [1913 Webster]

            The philosophy of our times does not expend itself
            in furious discussions on mere scholastic
            trivialities.                         --Lyon
                                                  Playfair.
      [1913 Webster]

WordNet (r) 3.0 (2006):

triviality
    n 1: the quality of being unimportant and petty or frivolous
         [syn: pettiness, triviality, slightness, puniness]
    2: a detail that is considered insignificant [syn:
       technicality, trifle, triviality]
    3: something of small importance [syn: triviality, trivia,
       trifle, small beer]

Moby Thesaurus II by Grady Ward, 1.0:

196 Moby Thesaurus words for "triviality":
   a continental, a curse, a damn, a darn, a hoot, absurdity,
   aimlessness, asininity, bagatelle, baseness, battiness, bauble,
   bean, bibelot, big deal, bit, bootlessness, brainlessness,
   brass farthing, buffoonery, button, cent, clownishness,
   crackpottedness, crankiness, craziness, curio, cursoriness,
   daffiness, daintiness, deficiency, delicacy, desipience,
   diminutiveness, eccentricity, emptiness, epidermis, exiguity,
   exiguousness, exteriority, failure, farce, farthing, fatuity,
   fatuousness, feather, fecklessness, fewness, fig, fleabite,
   flimsiness, folderol, folly, foolery, foolheadedness, foolishness,
   fribble, frippery, frivolity, frivolousness, fruitlessness,
   futility, gaud, gewgaw, giddiness, gimcrack, gloss, goofiness,
   hair, halfpenny, hill of beans, hollowness, idiocy, idleness,
   imbecility, imperfection, impotence, inadequacy, inanity,
   incompetence, inconsequence, inconsequentiality, inconsequentness,
   inconsiderableness, ineffectiveness, ineffectuality, inefficacy,
   ineptitude, insanity, insignificance, insufficiency, jest, joke,
   kickshaw, knickknack, knickknackery, levity, lightness, littleness,
   lunacy, madness, maladroitness, meagerness, meaninglessness,
   meanness, mediocrity, mere scratch, mindlessness, minikin,
   minuteness, minutiae, mockery, moderateness, molehill, niaiserie,
   no depth, no water, nugacity, nuttiness, otiosity, paltriness,
   peppercorn, pettiness, picayune, picayunishness, pin,
   pinch of snuff, pinprick, pointlessness, profitlessness, puniness,
   purposelessness, queerness, rap, rat race, red cent, rind,
   row of pins, rush, sappiness, scantiness, scratch, screwiness,
   senselessness, shabbiness, shallowness, shit, shoaliness,
   silliness, skin, slenderness, slightness, small, small beer,
   smallness, snap, sneeshing, sou, straw, stupidity, subnormality,
   superficiality, superficies, surface, technicality, the absurd,
   thoughtlessness, tininess, toy, trifle, triflingness, trinket,
   triteness, trivialness, tuppence, two cents, twopence,
   unimportance, unproductiveness, unprofitability, unprofitableness,
   unskillfulness, vacuity, valuelessness, vanity, vapidity, veneer,
   vicious circle, vulgarity, wackiness, weirdness, whim-wham,
   witlessness, worthlessness, zaniness, zanyism