A more thorough explanation:

Definition: An executory remainder is a type of future interest in property that is created in a third party and takes effect only if a specific condition is met. It is similar to a contingent remainder, but differs in that it does not require the termination of a prior estate to become possessory.

Example: John conveys his property to his son, Tom, for life, with the remainder to Tom's children. However, if Tom dies without any children, the property will go to John's daughter, Sarah. In this scenario, Sarah has an executory remainder because her interest in the property is contingent upon the condition that Tom dies without any children.

Explanation: The example illustrates how an executory remainder is created in a third party and takes effect only if a specific condition is met. In this case, Sarah's interest in the property is contingent upon the condition that Tom dies without any children. If Tom has children, then Sarah's interest in the property will not take effect. Therefore, an executory remainder is a type of future interest that is subject to a condition precedent.