Source : Webster's Revised Unabridged Dictionary (1913)

Inversion \In*ver"sion\, n. [L. inversio: cf. F. inversion. See
   {Invert}.]
   1. The act of inverting, or turning over or backward, or the
      state of being inverted.

   2. A change by inverted order; a reversed position or
      arrangement of things; transposition.

            It is just the inversion of an act of Parliament;
            your lordship first signed it, and then it was
            passed among the Lords and Commons.   --Dryden.

   3. (Mil.) A movement in tactics by which the order of
      companies in line is inverted, the right being on the
      left, the left on the right, and so on.

   4. (Math.) A change in the order of the terms of a
      proportion, so that the second takes the place of the
      first, and the fourth of the third.

   5. (Geom.) A peculiar method of transformation, in which a
      figure is replaced by its inverse figure. Propositions
      that are true for the original figure thus furnish new
      propositions that are true in the inverse figure. See
      {Inverse figures}, under {Inverse}.

   6. (Gram.) A change of the usual order of words or phrases;
      as, ``of all vices, impurity is one of the most
      detestable,'' instead of, ``impurity is one of the most
      detestable of all vices.''

   7. (Rhet.) A method of reasoning in which the orator shows
      that arguments advanced by his adversary in opposition to
      him are really favorable to his cause.

   8. (Mus.)
      (a) Said of intervals, when the lower tone is placed an
          octave higher, so that fifths become fourths, thirds
          sixths, etc.
      (b) Said of a chord, when one of its notes, other than its
          root, is made the bass.
      (c) Said of a subject, or phrase, when the intervals of
          which it consists are repeated in the contrary
          direction, rising instead of falling, or vice versa.
      (d) Said of double counterpoint, when an upper and a lower
          part change places.

   9. (Geol.) The folding back of strata upon themselves, as by
      upheaval, in such a manner that the order of succession
      appears to be reversed.

   10. (Chem.) The act or process by which cane sugar (sucrose),
       under the action of heat and acids or ferments (as
       diastase), is broken or split up into grape sugar
       (dextrose), and fruit sugar (levulose); also, less
       properly, the process by which starch is converted into
       grape sugar (dextrose).

   Note: The terms invert and inversion, in this sense, owe
         their meaning to the fact that the plane of
         polarization of light, which is rotated to the right by
         cane sugar, is turned toward the left by levulose.

Source : WordNet®

inversion
     n 1: the layer of air near the earth is cooler than an overlying
          layer
     2: abnormal condition in which an organ is turned inward or
        inside out (as when the upper part of the uterus is pulled
        into the cervical canal after childbirth)
     3: a chemical process in which the direction of optical
        rotation of a substance is reversed from dextrorotatory to
        levorotary or vice versa
     4: (genetics) a kind of mutation in which the order of the
        genes in a section of a chromosome is reversed
     5: the reversal of the normal order of words [syn: {anastrophe}]
     6: (counterpoint) a variation of a melody or part in which ll
        ascending intervals are replaced by descending intervals
        and vice versa
     7: a term formerly used to mean taking on the gender role of
        the opposite sex [syn: {sexual inversion}]
     8: turning upside down; setting on end [syn: {upending}]
     9: the act of turning inside out [syn: {eversion}, {everting}]