What is "estate in expectancy"

Expectance \Ex*pect"ance\, Expectancy \Ex*pect"an*cy\, n.

1. The act of expecting; expectation.
   --Milton.

2. That which is expected, or looked or waited for with interest; the object of expectation or hope.

   The expectancy and rose of the fair state.
   --Shak.

   Estate in expectancy (Law), one the possession of which a person is entitled to have at some future time, either as a remainder or reversion, or on the death of some one.
   --Burrill.