Emily Dickinson Lexicon

IN-VER'SION, n. [Fr. from L. inversio. See Invert.]

1. Change of order, so that the last becomes first and the first last; a turning or change of the natural order of things. 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.
2. Change of places, so that each takes the place of the other.
3. A turning backward; a contrary rule of operation. Problems in geometry and arithmetic are often proved by inversion, as division by multiplication, and multiplication by division.
4. In grammar, a change of the natural order of words; as, “of all vices, impurity is one of the most detestable,” instead of “impurity is one of the most detestable of all vices.”
5. In music, the change of position either of a subject or of a chord. Busby.