Reference · 107 terms

Legal terms

Plain-language definitions of the vocabulary the law actually uses — the people, the paperwork, the process, and the Latin.

People & the profession

Plaintiff: The party who starts a civil lawsuit, claiming a remedy from the defendant.
Defendant: The party a civil claim is brought against — or, in criminal cases, the person charged.
Accused: A person charged with a criminal offence, presumed innocent until the charge is proved.
Appellant: The party who brings an appeal, asking a higher court to change the decision below.
Respondent: The party answering an appeal or application — usually the one who won below.
Counsel: A party's lawyer or lawyers, especially when acting in court.
Barrister & solicitor: In England, two separate professions — courtroom advocates and client-facing lawyers. Canadian lawyers are admitted as both at once.
The Crown: The state in its legal person — the formal party prosecuting crime (R, for Rex) and the name for government in Commonwealth legal usage.
Intervener: A non-party allowed to make submissions in a case because its outcome affects them or an interest they represent.
Amicus curiae: 'Friend of the court' — someone appointed or permitted to assist the court with argument, without representing a party.
Self-represented litigant: A party conducting their case without a lawyer.
Fiduciary: A person who must act with loyalty in another's interest — trustee, agent, director — held by equity to strict duties.

Courts & judgments

Judgment: The court's decision in a case, with the reasons for it.
Order: A court's formal command — to pay, to produce, to stop — enforceable as such.
Precedent: A decided case used as authority for how a later case should be decided.
Ratio decidendi: The legal reasoning necessary to a decision — the part of a judgment that binds later courts.
Obiter dicta: Things said in passing in a judgment, beyond what the decision required — persuasive, not binding.
Distinguishing: Explaining why a precedent does not govern the present case because the facts differ in a way that matters.
Overrule: A higher (or the same, final) court declaring a precedent no longer good law.
Dissent: A judgment by a judge on the panel who disagrees with the result reached by the majority.
Concurrence: A judgment agreeing with the majority's result but for different or additional reasons.
Leave to appeal: Permission a party must obtain before certain appeals — the mechanism final courts use to choose their cases.
Appeal: Asking a higher court to review a decision for error — argued on the record, not by re-running the trial.
Quash: To set a decision or order aside, depriving it of legal effect.
Remit: To send a matter back to the court or decision-maker below to be dealt with again.
Injunction: An equitable order requiring someone to do, or stop doing, something — breach is contempt of court.
Damages: Money awarded as compensation for a legal wrong; the common law's default remedy.
Specific performance: An equitable order compelling a party to perform their contract — granted where damages would not do justice.
Declaration: A court's binding statement of the parties' legal position, without ordering anyone to do anything.
Contempt of court: Defying a court's order or authority — punishable by fine or imprisonment to protect the administration of justice.
Tribunal: A specialised decision-making body outside the courts — labour, human rights, immigration — subject to judicial review.
Citation: The standard reference identifying a case or statute — e.g. R v Oakes, [1986] 1 SCR 103.

Civil litigation

Cause of action: The legal basis of a claim — the recognised wrong (breach of contract, negligence) the facts are said to make out.
Pleadings: The formal documents in which each side states its claim or defence, framing the issues for trial.
Tort: A civil wrong other than breach of contract — negligence, defamation, trespass — remedied mainly by damages.
Negligence: The tort of causing foreseeable harm by failing to take reasonable care owed to another.
Liability: Legal responsibility for a wrong or obligation, and the exposure to its remedies.
Consideration: The something-of-value each side gives that makes a promise an enforceable contract in common law.
Estoppel: A doctrine preventing a party from going back on a position another has reasonably relied on.
Discovery: The pre-trial stage where parties must disclose relevant documents and answer questions under oath.
Limitation period: The statutory deadline for starting a claim — miss it and the claim is barred, however strong.
Settlement: The parties' agreement resolving a dispute without judgment — how the vast majority of civil cases actually end.
Class action: One representative suing on behalf of everyone with the same claim, with the result binding the whole class.
Costs: Litigation expenses. In the Commonwealth the loser usually pays part of the winner's costs; in the US each side generally bears its own.
Standing: The right to bring a case — normally requiring a direct stake in the outcome, relaxed for some public interest claims.
Burden of proof: The obligation to prove an assertion — resting on whoever makes it, to the standard the law sets.
Balance of probabilities: The civil standard of proof: more likely than not.
Vicarious liability: Liability for another's wrong because of the relationship — an employer answering for an employee's torts in the course of work.

Criminal process

Indictment: The formal document charging serious offences; 'indictable' offences are the graver class, tried with fuller procedure.
Summary offence: A less serious offence tried quickly before a judge alone, without jury or preliminary inquiry.
Arraignment: The formal reading of the charge in court, where the accused enters a plea.
Bail: Release from custody while awaiting trial, on conditions — called judicial interim release in Canada, where release is the constitutional default.
Plea: The accused's formal answer to a charge — guilty or not guilty.
Plea agreement: An agreement to plead guilty, usually to fewer or lesser charges or on a joint sentencing position.
Prosecution: The state's pursuit of a criminal charge — and the party conducting it (the Crown, in Commonwealth systems).
Disclosure: The prosecution's duty to hand the defence all relevant evidence, helpful or not — in Canada, the Stinchcombe obligation.
Beyond a reasonable doubt: The criminal standard of proof — far closer to certainty than to 'probably guilty'.
Acquittal: A verdict of not guilty: the charge was not proved to the criminal standard.
Conviction: A finding of guilt, by verdict or guilty plea, on which sentence follows.
Sentence: The punishment imposed on conviction — discharge, fine, probation, imprisonment — within limits set by statute.
Parole: Supervised release from prison before a sentence ends, granted and revocable by a parole authority.
Warrant: Judicial authorisation for an arrest or search — the default the law requires before police invade liberty or privacy.
Voir dire: A trial within a trial, held to decide a preliminary question — typically whether evidence is admissible — in the jury's absence.
Hearsay: An out-of-court statement offered to prove its own truth — presumptively inadmissible, because it cannot be cross-examined.
Privilege: Protection for certain communications — above all lawyer–client — from compelled disclosure in legal proceedings.
Subpoena: A command to attend court to testify or produce documents, on pain of contempt.
Perjury: Lying under oath in a judicial proceeding — itself a crime.
Reasonable doubt: The criminal standard of proof. Guilt must be proved beyond a reasonable doubt — not to an absolute certainty, but well beyond merely probably guilty.
Stay of proceedings: A court order halting a prosecution — permanently, or until a condition is met. It is the usual remedy for certain Charter breaches, such as unreasonable delay.
Indictable offence: A more serious class of criminal offence, carrying higher maximum penalties and often the right to a trial by jury.

Legislation & public law

Statute: A law enacted by a legislature — also called an act. Statutes override the common law where they speak.
Bill: A proposed statute making its way through the legislature; it becomes law on assent.
Royal assent: The Crown's formal approval that turns a bill into an act — by convention, never refused in modern practice.
Regulation: Binding rules made by the executive under authority delegated by a statute — where most modern law's detail lives.
Repeal: The revocation of a statute or provision by a later enactment.
Amendment: A formal change to a statute or constitution, made by the procedure the instrument requires.
Codification: Enacting an area of case law as a comprehensive statute — as Canada's Criminal Code did for crime.
Coming into force: The moment a statute takes legal effect — on assent, on a fixed date, or when proclaimed by the executive.
Reading down: Interpreting or trimming a statute narrowly so it stays within constitutional limits, rather than striking it entirely.
Severance: Striking only the invalid part of a statute and leaving the rest in force.
Reference: A government asking a court directly for an advisory opinion on a legal question — a distinctive Canadian practice, used for secession, Senate reform and more.
Writ: Historically, the royal order that started an action; today, the surviving prerogative writs — habeas corpus, certiorari, mandamus — are remedies against unlawful state action.
Mandamus: A court order compelling a public official to perform a duty the law requires of them.
Certiorari: The remedy quashing an unlawful decision of a lower court or tribunal — in the US, the writ by which the Supreme Court takes appeals.
Judicial review: A court's review of the legality of a decision made by government, a tribunal or a public body — distinct from an appeal, which reconsiders the merits.
Standard of review: How closely a court scrutinises an administrative decision on judicial review — presumptively reasonableness, with correctness for defined categories.
Procedural fairness: The duty of a public decision-maker to act fairly toward those affected — notice, a chance to be heard, and an unbiased decision-maker.
Natural justice: The older name for the core fairness rules: the right to be heard, and the rule against bias.
Reasonableness (standard of review): The deferential standard on judicial review, asking whether a decision is justified, transparent, intelligible, and within a range of acceptable outcomes.
Deference: The respect a reviewing court gives an administrative decision-maker's expertise, by not substituting its own view where the decision is reasonable.

Latin

Mens rea: 'Guilty mind' — the mental fault element of a crime.
Actus reus: 'Guilty act' — the external, physical element of a crime.
Habeas corpus: 'That you have the body' — the writ requiring a detention to be justified before a judge.
Stare decisis: 'To stand by things decided' — the doctrine of binding precedent.
Prima facie: 'At first appearance' — sufficient on its face, unless rebutted.
Res judicata: 'A matter decided' — a final judgment bars the same parties from relitigating the same dispute.
Sub judice: 'Under a judge' — before the courts, and therefore constrained from certain public comment.
Ultra vires: 'Beyond the powers' — an act outside the legal authority of the body that did it, and therefore invalid. Its opposite is intra vires.
Ex parte: Heard with only one party present — exceptional, and typically requiring urgency and full candour to the court.
De facto / de jure: In fact / in law — how things actually stand versus how the law formally regards them.
In camera: 'In a chamber' — a hearing closed to the public, as an exception to the open court principle.
Audi alteram partem: 'Hear the other side' — the first rule of natural justice.
Nemo judex in causa sua: 'No one may judge their own cause' — the rule against bias, the second rule of natural justice.
Inter alia: 'Among other things' — the drafter's signal that a list is not exhaustive.
Bona fide: 'In good faith' — honestly, without deceit or improper purpose.
Pro bono: 'For the good' — legal work done free of charge, in the public interest.
Functus officio: 'Having discharged the office' — a decision-maker who has ruled cannot reopen or change the decision.

Definitions are simplified for orientation, not advice. For the ideas behind the vocabulary, see legal concepts.