reversal
n. C / Un. a complete change in a situation, decision, or direction so that it becomes the opposite of what it was before.
n. a change to an opposite state, condition, or direction. Often describes a shift in legal decisions, political fortunes, or physical orientation.
The team suffered a sudden reversal of fortune.
The court's reversal of the previous ruling surprised many legal experts who expected the original decision to stand.
Economists warned that without structural reforms, the recent gains in employment could face a sharp reversal if global trade tensions continue to escalate.
From Middle English reversall; equivalent to reverse + -al.
From French réversal or Medieval Latin reversālis.
Often used with the preposition 'of' to specify what has changed ('a reversal of roles').