%inversion%

n. [ L. inversio: cf. F. inversion. See Invert. ] [ 1913 Webster ]

1. The act of inverting, or turning over or backward, or the state of being inverted. [ 1913 Webster ]

2. A change by inverted order; a reversed position or arrangement of things; transposition. [ 1913 Webster ]

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. [ 1913 Webster ]

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. [ 1913 Webster ]

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. [ 1913 Webster ]

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. [ 1913 Webster ]

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.” [ 1913 Webster ]

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. [ 1913 Webster ]

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. [ 1913 Webster ]

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. [ 1913 Webster ]

10. (Chem.) The act or process by which cane sugar (sucrose), under the action of heat and acids or enzymes (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). [ 1913 Webster ]

☞ 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. [ 1913 Webster ]

11. (Meteorology) A reversal of the usual temperature gradient of the atmosphere, in which the temperature increases with increased altitude, rather than falling. Called also temperature inversion. This condition in the vicinity of cities can give rise to a severe episode of atmospheric pollution, as it inhibits normal circulation of the air. [ PJC ]

12. (Electricity) The conversion of direct current into alternating current; the inverse of rectification. See inverted rectifier. [ PJC ]

13. (Genetics) A portion of the genome in which the DNA has been turned around, and runs in a direction opposite to its normal direction, and consequently the genes are present in the reverse of their usual order. [ PJC ]