Source : Webster's Revised Unabridged Dictionary (1913)

Fraction \Frac"tion\, n. [F. fraction, L. fractio a breaking,
   fr. frangere, fractum, to break. See {Break}.]
   1. The act of breaking, or state of being broken, especially
      by violence. [Obs.]

            Neither can the natural body of Christ be subject to
            any fraction or breaking up.          --Foxe.

   2. A portion; a fragment.

            Some niggard fractions of an hour.    --Tennyson.

   3. (Arith. or Alg.) One or more aliquot parts of a unit or
      whole number; an expression for a definite portion of a
      unit or magnitude.

   {Common, or Vulgar}, {fraction}, a fraction in which the
      number of equal parts into which the integer is supposed
      to be divided is indicated by figures or letters, called
      the denominator, written below a line, over which is the
      numerator, indicating the number of these parts included
      in the fraction; as 1/2, one half, 2/5, two fifths.

   {Complex fraction}, a fraction having a fraction or mixed
      number in the numerator or denominator, or in both.
      --Davies & Peck.

   {Compound fraction}, a fraction of a fraction; two or more
      fractions connected by of.

   {Continued fraction}, {Decimal fraction}, {Partial fraction},
      etc. See under {Continued}, {Decimal}, {Partial}, etc.

   {Improper fraction}, a fraction in which the numerator is
      greater than the denominator.

   {Proper fraction}, a fraction in which the numerator is less
      than the denominator.

Improper \Im*prop"er\, a. [F. impropre, L. improprius; pref. im-
   not + proprius proper. See {Proper}.]
   1. Not proper; not suitable; not fitted to the circumstances,
      design, or end; unfit; not becoming; incongruous;
      inappropriate; indecent; as, an improper medicine;
      improper thought, behavior, language, dress.

            Follow'd his enemy king, and did him service,
            Improper for a slave.                 --Shak.

            And to their proper operation still, Ascribe all
            Good; to their improper, Ill.         --Pope.

   2. Not peculiar or appropriate to individuals; general;
      common. [Obs.]

            Not to be adorned with any art but such improper
            ones as nature is said to bestow, as singing and
            poetry.                               --J. Fletcher.

   3. Not according to facts; inaccurate; erroneous.

   {Improper diphthong}. See under {Diphthong}.

   {Improper feud}, an original feud, not earned by military
      service. --Mozley & W.

   {Improper fraction}. See under {Fraction}.

Source : WordNet®

improper fraction
     n : a fraction whose numerator is larger than the denominator