A more thorough explanation:

Definition: A plaintiff who brings an action in another person's name in common-law pleading. This is also known as a usee. For instance, if a person named A is an assignee of a chose in action and has to sue in someone else's name, the assignor B would appear first on the petition's title: "B for the Use of A against C."

Example: John is a contractor who has a contract with a homeowner, but the homeowner refuses to pay him. John can sue the homeowner in court, but he can also use a plaintiff to sue on his behalf. In this case, John would be the use plaintiff, and the person suing the homeowner would be the usee.

Explanation: The example illustrates the use of a plaintiff in common-law pleading. John, the contractor, is the use plaintiff, and the person suing the homeowner is the usee. The use plaintiff is necessary when the person who has the right to sue cannot do so in their own name.