The Collaborative International Dictionary of English v.0.48:

Trifle \Tri"fle\, v. t.
   1. To make of no importance; to treat as a trifle. [Obs.]
      --Shak.
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   2. To spend in vanity; to fritter away; to waste; as, to
      trifle away money. "We trifle time." --Shak.
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The Collaborative International Dictionary of English v.0.48:

Trifle \Tri"fle\, n. [OE. trifle, trufle, OF. trufle mockery,
   raillery, trifle, probably the same word as F. truffe
   truffle, the word being applied to any small or worthless
   object. See Truffle.]
   1. A thing of very little value or importance; a paltry, or
      trivial, affair.
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            With such poor trifles playing.       --Drayton.
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            Trifles light as air
            Are to the jealous confirmation strong
            As proofs of holy writ.               --Shak.
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            Small sands the mountain, moments make year,
            And frifles life.                     --Young.
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   2. A dish composed of sweetmeats, fruits, cake, wine, etc.,
      with syllabub poured over it.
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The Collaborative International Dictionary of English v.0.48:

Trifle \Tri"fle\, v. i. [imp. & p. p. Trifled; p. pr. & vb. n.
   Trifling.] [OE. trifelen, truflen. See Trifle, n.]
   To act or talk without seriousness, gravity, weight, or
   dignity; to act or talk with levity; to indulge in light or
   trivial amusements.
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         They trifle, and they beat the air about nothing which
         toucheth us.                             --Hooker.
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   To trifle with, to play the fool with; to treat without
      respect or seriousness; to mock; as, to trifle with one's
      feelings, or with sacred things.
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WordNet (r) 3.0 (2006):

trifle
    n 1: a cold pudding made of layers of sponge cake spread with
         fruit or jelly; may be decorated with nuts, cream, or
         chocolate
    2: a detail that is considered insignificant [syn:
       technicality, trifle, triviality]
    3: something of small importance [syn: triviality, trivia,
       trifle, small beer]
    v 1: waste time; spend one's time idly or inefficiently [syn:
         piddle, wanton, wanton away, piddle away, trifle]
    2: act frivolously [syn: frivol, trifle]
    3: consider not very seriously; "He is trifling with her"; "She
       plays with the thought of moving to Tasmania" [syn: dally,
       trifle, play]