A more thorough explanation:

Definition: An aid prayer is a request made by a life tenant or someone who holds less than a fee simple to bring in another person who holds an interest in the estate, such as a reversioner or remainderman, to help defend the title.

Example: John is a life tenant of a property, but he is being sued by someone claiming to have a better title to the property. John can make an aid prayer to bring in the reversioner, who holds an interest in the estate, to help defend the title.

Explanation: In this example, John is asking the court to bring in the reversioner to help him defend his title to the property. The reversioner has an interest in the estate and can help John in the lawsuit. This is an example of an aid prayer in action.