Class definition
A class definition is the written description of who is in a class action, usually by what they bought or used, where, and when.
Also called: definition of the class, settlement class definition, who is included in the class
A class definition is the written description of who is in a class action, usually by what they bought or used, where, and when.
What it means
A class definition is the written description of who belongs to a class action. It usually names what the group bought or used, where they lived or bought it, and the dates when it happened. It often lists who is left out, such as the company's employees.
Rule 23 requires the order that certifies a class to define it. The notice sent to class members has to state the definition in plain, easily understood language. A good definition is specific enough that you can tell from your own records whether you fit. It is also what a settlement administrator measures your claim against.
The definition can change before final judgment. The one in the original complaint may be broader or narrower than the one in the final settlement. The version in the court-approved settlement and notice decides who can claim.
What it means for you
The class definition decides whether you can file, which payment tier applies and which deadlines affect you. Compare it to your own records one piece at a time: the product or service, the dates, the place and any exclusions. A small mismatch, such as an account opened a month after the end date, can mean you are not covered. Owed compares your answers with the class definitions of open settlements to find ones you may qualify for. The settlement administrator and the court make the final call, so read the definition on the official settlement website before you file.
Example
Say a settlement covers "everyone in the United States who bought a Model B air fryer between January 1, 2022 and June 30, 2024, except company employees." You bought one in September 2022 at a store, so you fit. Your neighbor bought the same model in August 2024, after the end date, so she doesn't. A cousin who works for the company is excluded, even though he bought one in 2023.
FAQ
On the official settlement website, usually under a heading like "Who is included" or "Am I a class member," and in the long-form notice and claim form. Use the website named in the court-approved notice, not a link from an unexpected message.
Check each piece against your records, such as order history, statements or account emails. If you still can't tell, the settlement website's contact page or the administrator's help line can answer questions about who is covered. The administrator decides whether your claim is valid.
Related terms
- Fed. R. Civ. P. 23, Class Actions (Cornell Legal Information Institute)
- Federal Rules of Civil Procedure, as of Dec. 1, 2025 (U.S. Courts)
Updated Oct 18, 2026. Plain-English definitions for general information — not legal or tax advice.