A more thorough explanation:

An accelerated remainder is a type of future interest in real property that arises in a third person who is intended to take after the natural termination of the preceding estate. It occurs when the gift to the preceding beneficiary fails, and the remainder passes to the remainderman. For example, if a grant is “to A for life, and then to B,” but A dies before B, B's future interest becomes an accelerated remainder.

Accelerated remainder is also known as remainder estate or estate in remainder. It is different from other types of remainders, such as vested remainder, contingent remainder, and cross-remainder, which have their own specific characteristics and conditions.

Overall, an accelerated remainder is a way to ensure that the property passes to a designated person after the initial beneficiary's death or failure to fulfill the conditions of the grant.