(~s)
1.
A ~ of a process, policy, or trend is a complete change in it.
The Financial Times says the move represents a complete ~ of previous US policy...
N-COUNT: oft N of n
2.
When there is a role ~ or a ~ of roles, two people or groups exchange their positions or functions.
When children end up taking care of their parents, it is a strange role ~ indeed.
N-COUNT: n N, N of n