Reference

A Plain-Language Glossary of Constitutional Terms

Constitutional writing is full of words that look ordinary and are not. Some, like quorum or certiorari, announce themselves as technical. Others, like commerce or due process, slip past because they sound like everyday English while carrying two centuries of argument.

These definitions are meant to get you through a sentence, not to settle a dispute. Where a term is genuinely contested we say so rather than pick a side. For the authoritative treatment of any clause, go to the Constitution Annotated; Cornell Law School's Legal Information Institute keeps a free annotated text as well.

A to C

Advice and consent: The Senate's share in two presidential powers under Article II. A treaty needs the concurrence of two-thirds of the senators present; most senior appointments need a simple majority.
Amendment: A formal change to the Constitution, added at the end of the document rather than woven into the original wording. Twenty-seven have been ratified.
Appropriation: A law that authorizes money to be spent from the Treasury. Article I, Section 9 says no money may be drawn from the Treasury except by appropriations made by law.
Article V convention: The second route to proposing amendments: Congress calls a convention when the legislatures of two-thirds of the states apply for one. It has never been used; all twenty-seven amendments so far came from Congress.
Bicameral: Having two chambers. Congress is bicameral, consisting of the House of Representatives and the Senate.
Bill of attainder: A law that singles out a person or group and punishes them without a trial. Article I forbids both Congress and the states to pass one.
Bill of Rights: The first ten amendments, proposed together and ratified in 1791. Our page on the Bill of Rights takes them clause by clause.
Cabinet: The heads of the executive departments, acting as the president's advisers. The word never appears in the Constitution, which mentions only the principal officer in each of the executive departments.
Checks and balances: The arrangement by which each branch can block or condition part of what the others do: the veto and the override, confirmation, impeachment, appropriations, judicial rulings.
Commerce Clause: Article I, Section 8's grant of power to Congress to regulate commerce with foreign nations, among the states, and with the Indian tribes. How far that reaches is one of the most argued questions in constitutional law.
Concurrent powers: Powers that federal and state governments both hold, such as taxing, borrowing, and running court systems. The phrase is descriptive; it does not appear in the text.
Contracts Clause: Article I, Section 10's bar on any state passing a law impairing the obligation of contracts.

D to F

Delegated powers: Powers handed to the federal government through the Constitution rather than held by it inherently. Often used interchangeably with enumerated powers.
Dicta: Passages in a court opinion that were not necessary to decide the case. They can be persuasive, but they do not bind later courts the way a holding does.
Due process: The requirement of fair procedure before government takes life, liberty, or property. The Fifth Amendment applies it to the federal government and the Fourteenth applies it to the states.
Electoral College: The body that formally elects the president. Each state appoints electors equal to its combined number of senators and representatives. The Twelfth Amendment revised the original voting procedure, and the Twenty-Third gave the District of Columbia electors.
Enumerated powers: Powers actually listed in the text, chiefly the list in Article I, Section 8. The premise behind the list is that the federal government holds granted powers rather than general ones.
Establishment Clause: The opening words of the First Amendment, barring laws respecting an establishment of religion.
Ex post facto law: A law that reaches backward, making conduct criminal after it happened or increasing the punishment after the fact. Article I forbids them to Congress and to the states.
Executive order: A written directive from the president to the executive branch. The Constitution does not mention them, so their authority has to come from a statute or from the president's own constitutional powers.
Federalism: The division of authority between one national government and fifty state governments, each with its own sphere. Our page on federalism explains where the line is drawn and why it moves.
Free Exercise Clause: The First Amendment's protection of religious practice, following the Establishment Clause in the same sentence.
Full faith and credit: Article IV's rule that each state must respect the public acts, records, and court judgments of every other state.

G to J

Habeas corpus: A court order requiring an official holding someone to produce the prisoner and justify the detention. Article I permits suspending it only in cases of rebellion or invasion, when the public safety requires it.
Impeachment: The House's power to charge a federal officer with misconduct: the accusation, not the removal. The Senate tries the case, conviction requires two-thirds of the members present, and the penalty is limited to removal and disqualification from future office.
Incorporation: The process by which most of the Bill of Rights, originally a set of limits on the federal government alone, came to apply against the states through the Fourteenth Amendment.
Judicial review: The power of courts to decide that a law or official act conflicts with the Constitution and to refuse it effect. The text does not say so in as many words; the Supreme Court set the principle out in Marbury v. Madison in 1803. See our page on judicial review.
Jurisdiction: A court's authority to hear a particular case. Article III distinguishes the Supreme Court's original jurisdiction, where a case begins there, from its appellate jurisdiction, where it reviews a decision made below.

K to P

Majority opinion: The opinion joined by a majority of the participating justices. It states the court's reasoning and binds lower courts. Separate concurrences and dissents do not.
Necessary and Proper Clause: The final clause of Article I, Section 8, allowing Congress to make the laws needed to carry its other powers into effect. Sometimes called the Elastic Clause, and how far it stretches has been argued since the 1790s.
Originalism: A family of approaches that read the Constitution according to what its words were understood to mean when they were adopted. One method among several; our page on interpretation sets the main ones side by side.
Preamble: The single opening sentence beginning with the words We the People. It states the document's purposes and grants no power by itself.
Precedent: An earlier decision that governs how a later, similar case should be resolved.

Q to S

Quorum: The number of members who must be present for a chamber to do business. Article I sets it at a majority of each house.
Ratification: The formal approval that makes a text binding. The Constitution itself required nine states under Article VII; an amendment requires three-fourths of the states under Article V, acting through legislatures or conventions as Congress specifies.
Reserved powers: Powers neither given to the federal government nor denied to the states, which the Tenth Amendment reserves to the states or to the people.
Separation of powers: The assignment of legislative, executive, and judicial functions to three different branches. Our page on separation of powers goes through how the three articles divide the work.
Stare decisis: Latin for standing by things decided. The practice of following precedent unless there is strong reason to depart from it.
Supremacy Clause: Article VI's declaration that the Constitution, the federal laws made under it, and treaties are the supreme law of the land, binding on state judges.

T to W

Textualism: An approach that gives priority to the ordinary meaning of the words actually enacted, rather than to the purposes or intentions behind them.
Treaty: An agreement with a foreign nation, made by the president with the advice and consent of two-thirds of the senators present.
Unenumerated rights: Rights not written down in the text. The Ninth Amendment says that listing some rights must not be taken to deny others retained by the people, though which rights those are is heavily contested.
Veto: The president's return of a bill to Congress with objections. Congress may override with two-thirds of each chamber. If the president neither signs nor returns a bill within ten days, Sundays excepted, while Congress remains in session, it becomes law without a signature.
Writ of certiorari: The order by which the Supreme Court agrees to review a lower court's decision. The Court grants only a small fraction of the petitions it receives, and by its own long-standing practice four justices must agree to take a case.

Using this glossary

Terms are grouped by letter range so that a word you half remember is easy to find by scanning. If you are working through the text a portion at a time, keep this page beside our daily reading plan and look up one word per sitting. For the source rather than the summary, our primary sources guide lists the free authoritative editions, and the Supreme Court's own website publishes its opinions and orders directly. Suggestions for terms to add are welcome through our contact page.