A glossary of legal terms is most useful when you need it fast: a contract just landed on your desk, a summons arrived, or a probate court sent a notice. The definitions below cover the words that come up most often in courtrooms, criminal charges, civil disputes, contracts, property transfers, estate planning, and appeals. Each entry explains what the term means and, where it matters, what it means for you.
Courtroom and Procedural Terms
Jurisdiction is whether a particular court has the authority to hear a case at all. Federal courts handle a narrow set of disputes: cases involving federal law, cases where the U.S. government is a party, and cases between residents of different states where the amount at stake exceeds $75,000.1United States District Court. What Kinds of Cases Belong in Federal Court (Subject Matter Jurisdiction)? A case that doesn’t fit one of those categories gets dismissed no matter how strong the underlying facts are.
Venue is a separate question from jurisdiction. Even when a court has authority to hear a type of case, venue asks which geographic district should hear it, usually where the events happened or where the parties live.
Service of process is the delivery of the summons and complaint to the defendant. Filing a lawsuit and paying the filing fee gets the case on the docket, but the case doesn’t officially begin against the defendant until they’ve been properly served. Under federal rules, anyone at least 18 and not a party to the case can hand-deliver the documents, leave them at the defendant’s home with a resident of suitable age, or deliver them to an authorized agent.2Legal Information Institute. Rule 4 – Summons A plaintiff can also ask the defendant to waive formal service; refusing without good cause can force the defendant to pay the expenses of doing it the hard way.
Motion. A formal written request asking a judge to take a specific action. A motion to dismiss argues that even if everything the plaintiff says is true, there’s no legal basis for the case. A motion for summary judgment asks the judge to decide the case without a trial because the key facts aren’t in dispute and one side is clearly entitled to win under the law.3Legal Information Institute. Rule 56 – Summary Judgment
Affidavit. A written statement signed under oath, typically before a notary public or court officer. Lying in one can bring perjury charges.4National Institute of Justice. Law 101 – Legal Guide for the Forensic Expert – Legal Requirements of an Affidavit
Brief. A written legal argument citing statutes and past court decisions to persuade a judge to rule a certain way. Briefs contain legal reasoning; affidavits contain sworn facts.
Pro se litigant. A person who represents themselves in court without a lawyer. Courts hold them to the same procedural rules as attorneys, so a missed deadline or filing mistake can end a case before it’s heard on the merits.
Petitioner and respondent. In family and administrative courts, the party starting the case is usually called the petitioner and the other side the respondent, rather than plaintiff and defendant.
Criminal Law Terms
Felony. The most serious category of criminal offense. Under federal law, felonies are classified by letter grade based on maximum prison time: Class A up to life imprisonment, Class B up to 25 years, down to Class E for sentences just over one year.5Office of the Law Revision Counsel. 18 US Code 3559 – Sentencing Classification of Offenses Federal fines for a felony can reach $250,000 for individuals and $500,000 for organizations.6Office of the Law Revision Counsel. 18 USC 3571 – Sentence of Fine
Misdemeanor. A less serious offense. Class A misdemeanors carry up to one year of jail time, Class B up to six months, and Class C up to 30 days.5Office of the Law Revision Counsel. 18 US Code 3559 – Sentencing Classification of Offenses Fines for a Class A misdemeanor can reach $100,000.6Office of the Law Revision Counsel. 18 USC 3571 – Sentence of Fine
Arraignment. The court appearance shortly after arrest where the judge reads the charges and the defendant enters a plea: guilty, not guilty, or no contest (nolo contendere).7United States Department of Justice. Initial Hearing / Arraignment
Indictment. A formal charge issued by a grand jury, a group of citizens who review the prosecutor’s evidence and decide whether there’s enough to bring someone to trial. Grand jury indictments are required for many federal felony cases before they can proceed.8United States Department of Justice. Justice Manual 9-11.000 – Grand Jury
Burden of proof. The obligation to prove a fact in dispute. In criminal cases, the prosecution carries it.
Beyond a reasonable doubt. The highest standard of proof in the legal system. It applies to criminal cases and requires the evidence to leave the jury firmly convinced of the defendant’s guilt.9Legal Information Institute. Beyond a Reasonable Doubt
Plea bargain. An agreement in which the defendant pleads guilty, often to a lesser charge, avoiding the uncertainty of a trial.
Acquittal and conviction. An acquittal means the jury found the prosecution failed to meet its burden. A conviction means it succeeded and creates a permanent criminal record that can affect employment, housing, and other opportunities.
Expungement vs. Record Sealing
Two tools exist for dealing with a criminal record after the fact, and the difference matters. Expungement (sometimes called expunction) effectively erases the record; courts treat the arrest or conviction as though it never happened, and the associated files are destroyed. Record sealing keeps the record on file but blocks public access. Sealed records stay visible to certain government agencies but are hidden from the general public and most private employers.
Eligibility depends on the jurisdiction and the type of offense. Expungement is generally reserved for arrests that didn’t lead to a conviction, dismissed charges, or pardoned offenses. Sealing tends to be available for a broader range of cases but still requires a judge’s approval. At the federal level, expungement orders are extremely rare and no comprehensive federal statute governs the process, so most expungement and sealing activity happens in state courts under state law.
Civil Litigation and Tort Terms
Tort. A civil wrong where one party’s actions, or failure to act, cause harm to another.
Negligence. The most common tort. It requires showing that someone failed to exercise the level of care a reasonable person would have used in the same circumstances.
Liability. The legal responsibility one party bears for harm caused.
Preponderance of the evidence. The standard of proof in most civil cases. The plaintiff has to convince the judge or jury that there’s a greater than 50 percent chance their version is correct, sometimes described as “more likely than not.”10Legal Information Institute. Preponderance of the Evidence
Discovery. The pretrial phase where both sides exchange information. The main tools are depositions (formal interviews under oath), interrogatories (written questions the other side must answer under oath), requests for documents, and requests for admissions.11U.S. Equal Employment Opportunity Commission. A Guide to the Discovery Process for Unrepresented Complainants
Compensatory damages. Money that reimburses the plaintiff for specific losses: medical bills, lost wages, repair costs, and similar out-of-pocket expenses.
Punitive damages. A separate, rarer category meant to punish especially reckless or intentional misconduct and deter similar behavior.
Injunction. A court order directing someone to do something or to stop doing something, such as halting construction on a disputed property. Courts grant injunctions when money alone can’t fix the problem.12Legal Information Institute. Injunction
Statutes of Limitation and Filing Deadlines
Statute of limitations. A deadline for filing a lawsuit. Miss it, and the court will almost certainly throw out the case regardless of how strong the evidence is. Deadlines vary by the type of claim and the jurisdiction. Personal injury claims commonly run two to six years depending on the state. Breach of contract claims can run anywhere from three to ten years, with written contracts often getting a longer window than oral ones.
Tolling. The pausing of a limitations deadline. The most common reason is age: if the injured person was a minor when the harm occurred, the clock often doesn’t start running until they turn 18. Mental incapacity and fraud by the defendant can also toll a deadline.
Discovery rule. A related concept that delays the start of the limitations period until the injured person knew, or reasonably should have known, about the harm. It comes up frequently in medical malpractice, where a surgical error might not become apparent for months or years.
Criminal cases have their own limitations periods, but the most serious offenses, including murder, typically have no deadline at all.
Contract Terms
Consideration. What each side gives up to get what they want under a contract. Usually it’s money, but it can be a promise to do something, a promise not to do something, or an exchange of goods. Without consideration, an agreement is treated as a gift and generally can’t be enforced.
Clause. An individual provision within a contract that spells out a specific right or duty.
Breach of contract. A failure to perform as promised. Waiting too long to address a breach can weaken or eliminate the right to seek damages.
Statute of Frauds
Not every agreement has to be in writing, but certain categories of contracts are unenforceable unless they are. This rule, the statute of frauds, generally covers:
- Real estate transactions, meaning any contract involving the sale or transfer of an interest in land.
- Sales of goods worth $500 or more, under the Uniform Commercial Code.13Legal Information Institute. UCC 2-201 – Formal Requirements; Statute of Frauds
- Agreements that by their terms cannot be fully performed within one year of being made.
- Promises to pay someone else’s debt, known as suretyship agreements.
- Contracts made in consideration of marriage, most commonly prenuptial agreements.
An oral agreement in one of these categories is essentially unenforceable even if both parties fully intended to honor it.
Property Terms
Lien. A legal claim against property that secures a debt. A contractor who isn’t paid for work on your house can file a lien that attaches to the property, typically preventing a sale or refinance until the debt is resolved.
Easement. The right to use a portion of someone else’s land for a specific purpose, such as a utility company running lines through a backyard or a neighbor using a shared driveway.
Title. The legal concept of ownership.
Deed. The document that transfers ownership from one person to another.
Title insurance. Coverage that protects a buyer against problems surfacing after a purchase, such as an undiscovered lien or a competing ownership claim from an earlier transaction.
Joint tenancy with right of survivorship. A form of co-ownership in which one owner’s share automatically passes to the surviving owner at death.
Tenancy in common. A form of co-ownership in which each owner’s share passes to their own estate rather than to the co-owner, meaning it goes through probate and could end up with someone the surviving owner never chose. The distinction rarely comes up until someone dies, and by then it’s too late to change.
Power of Attorney
A power of attorney authorizes someone (the agent) to act on your behalf in financial, legal, or medical matters.14Consumer Financial Protection Bureau. What Is a Power of Attorney (POA)? A standard power of attorney ends if the person who granted it becomes mentally incapacitated, which is often when it’s needed most. A durable power of attorney survives incapacity and remains in effect until it’s revoked or the principal dies. For future planning, the durable version is almost always the one people want.
Estate Planning and Probate Terms
Will. A formal document stating how you want your property and assets distributed after your death.
Intestate. Dying without a valid will. State law then decides who inherits, usually in an order of priority (spouse, children, parents, siblings) that may not match what the person would have chosen.15Legal Information Institute. Intestacy
Probate. The court-supervised process of validating a will and distributing the deceased person’s assets. Costs generally run between 3 and 7 percent of the total estate value, covering court fees, appraisal costs, and legal representation.
Executor. The person named in a will to manage the probate process.
Administrator. The person the court appoints to handle those same duties when there’s no will or no named executor.
Trust. A legal arrangement in which a trustee manages assets for named beneficiaries. Because the trust technically owns the assets, they pass outside probate, which is why trusts are the most common probate-avoidance tool.
Codicil. A supplement that changes an existing will without requiring a full rewrite. Courts require the same formalities, including witnesses and signatures, as they do for the will itself.16Legal Information Institute. Codicil
Advance Directives
An advance directive covers medical decisions if you become unable to communicate. It typically has two parts. A living will spells out treatment preferences, such as whether you want life-sustaining measures in a terminal condition. A healthcare power of attorney (also called a healthcare proxy) names a specific person to make medical decisions when situations arise that the living will didn’t anticipate. The living will states what you want; the healthcare agent handles everything else.
Appellate Terms
Appeal. A request that a higher court review a lower court’s decision for legal errors. Appeals don’t retry the facts. The appellate court examines the trial record and the legal arguments to decide whether the law was applied correctly.
Deadlines are strict and short. In federal civil cases, a notice of appeal must be filed within 30 days of the judgment. In federal criminal cases, a defendant has 14 days.17Legal Information Institute. Rule 4 – Appeal as of Right – When Taken Missing these deadlines almost always forfeits the right to appeal.
An appellate court can do several things with a case:
- Affirm. Uphold the lower court’s result; the original decision stands.
- Vacate. Void the lower court’s decision, wiping it out as though it never happened.
- Remand. Send the case back to the lower court for further proceedings, often with instructions to apply a different legal standard or reconsider specific issues.
- Reverse. Overturn the lower court’s ruling and replace it with the opposite outcome.
Writ of certiorari. A petition asking the U.S. Supreme Court to review a case, typically after a loss in a federal appeals court or state supreme court. The Court is not obligated to hear any of them. Four of the nine justices must vote to accept a case, and out of roughly 7,000 petitions filed each year the Court takes only 100 to 150.18United States Courts. Supreme Court Procedures The Court generally selects cases that raise unresolved questions of national significance or where different federal appeals courts have reached conflicting conclusions on the same legal issue.