Affirm
Affirm: A word with two common legal meanings. First, an appeals court affirms when it upholds the lower court's judgment or order, leaving it in place; the decision is called an affirmance. The court can also affirm in part and reverse in part. Second, a person affirms when he or she makes a solemn declaration that a statement is true, instead of swearing an oath. The law treats an affirmation the same as an oath. Under 1 U.S.C. § 1, "oath" includes affirmation, and "sworn" includes affirmed. Federal Rule of Evidence 603 requires a witness to "give an oath or affirmation to testify truthfully," and Federal Rule of Civil Procedure 43(b) provides that "When these rules require an oath, a solemn affirmation suffices." A false affirmation can be perjury, just like a false oath.
What affirm means
Put simply, affirm is part of the working vocabulary of a civil case. The short definition above covers the usual meaning. Still, a specific rule, statute or contract can give it a narrower meaning. For that reason, check how it is used in your own documents.
Where affirm comes up
The term is used across many kinds of cases. For example, you may see it in pleadings, motions and court orders. To see it in context, browse the motions and procedures library or the Learn the Law topics.
Read the source: 1 U.S.C. § 1, Fed. R. Evid. 603.
How to research the term
To research affirm, begin with the rule, statute or contract where the word is used. Each one can give it a slightly different meaning. Then compare that text with how courts in your area have applied it. Also check the local rules of your court, since they can add requirements. If your case is in state court, the state rules control. So start with our state procedures guide to find them. In the end, always confirm that the source you rely on is current.
You can read the current federal court rules online for free.
Related legal terms
- Admission: a statement acknowledging that something is true.
- Admit: to acknowledge that something is true, or to allow something in.
- Affiant: the person who makes and signs an affidavit, swearing or affirming that its contents are true.
- Affidavit: a written statement of facts sworn to before an officer authorized to administer oaths.
Why precise terms matter
Courts read legal terms closely. As a result, knowing the exact meaning of a word helps you follow orders, rules and filings. Each glossary entry on Lawtopolis is short on purpose and links to the pages where the term is used.
Sources
Sources last reviewed: 2026-10-24
Lawtopolis provides legal information and education, not legal advice. Using this site does not create an attorney-client relationship. Laws and court rules vary by jurisdiction and change over time; verify every authority against the official source and consult a licensed attorney in your jurisdiction about your situation.