rules against perpetuities

Noun

rule against perpetuities (plural rules against perpetuities)

1. (singular, singular-only) The rule that prevents a testator or other transferor of property from controlling further transfer of his property more than twenty-one years after the death of anyone alive at the time of the original transfer who may have some interest in the transfer.
2. (broadly, countable) Any rule that prevents a testator or other transferor of property from controlling further transfer of his property beyond a certain length of time.