noun
1.
a causing to move or face in an opposite direction or to appear in an inverted position
a reversal in policy
the reversal of objects seen through a simple lens
Synonyms: about-face, changeabout, inversion, reverse, reversement, reversion, right-about, right-about-face, turn, turnabout, turning, volte-face
Related Word: bouleversement, overturning
2.
Synonyms: setback , backset, check, reverse