\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.