Shifting clanse
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
A shifting clause in a settlement is a clause by which some other mode of devolution is substituted for that primarily prescribed. Examples of shifting clauses are; The ordinary name and arms clanse, and the clause of less frequent occurrence by which a settled estate is destined as the foundation of a second family, in the event of the elder branch becoming otherwise enriched. These shifting clauses take effect under the statute of uses.
Sweet.