A more thorough explanation:

A shifting clause is a legal term that refers to a clause in a settlement of an estate that prescribes a substituted mode of devolution. This means that the clause specifies a different way for the estate to be passed down or distributed than what would normally occur under the law.

For example, a shifting clause might state that if the original beneficiary of an estate dies before reaching a certain age, the estate will then pass to a different beneficiary instead of being distributed according to the laws of inheritance. This clause "shifts" the way the estate is distributed from the default method to a different one.

Another example of a shifting clause might be one that specifies that if a certain condition is met, such as the birth of a child or the completion of a certain project, the estate will then pass to a different beneficiary. This clause again "shifts" the way the estate is distributed based on a specific condition being met.

Overall, shifting clauses are used to provide more specific instructions for how an estate should be distributed, rather than relying solely on the default laws of inheritance.