Shifting Use
Dictionary of Terms and Phrases Used in American or English Jurisprudence · Benjamin Vaughan Abbott · 1879
Dictionary of Terms and Phrases Used in American or English Jurisprudence
A secondary or executory use, which, when executed, operates in derogation of a preceding estate; as where land is conveyed to the use of A and bis heirs, with proviso that, when B pays a certain sum of money, then to the use of C and his heirs.
Wharton.