Definition
Injunctions are court orders commanding a party to do something (mandatory injunction) or to refrain from doing something (prohibitory injunction). They are equitable remedies, historically issued by courts of chancery and today available in federal and most state courts whenever a legal remedy — typically monetary damages — would be inadequate to address the harm at issue.
An injunction runs against a party personally. Violation of an injunction is enforceable through the court's contempt power, which distinguishes it from a damages judgment and gives it practical teeth as a litigation tool.
Injunctions take several forms depending on timing and duration:
1. Temporary Restraining Order (TRO): An emergency injunction issued on short notice, or sometimes without notice to the opposing party, to preserve the status quo until a fuller hearing can be held. Short-lived by design.
2. Preliminary Injunction: Issued after notice and a hearing, operative during the pendency of litigation. The court is not finally resolving the merits — it is deciding whether to freeze or preserve circumstances while the case proceeds.
3. Permanent Injunction: Issued as part of a final judgment after full adjudication on the merits. Despite the name, it need not last forever; it is "permanent" in the sense that it resolves the matter rather than being provisional.
Common Language
Modern common usage (Wiktionary): Plural of injunction. In ordinary use, an injunction is understood as a court-ordered prohibition — telling someone to stop doing something.
Historical common usage (Webster's 1913): "The act of enjoining; the act of directing, commanding, or prohibiting. A precept or order; a mandate; specifically (Law), a writ or process, granted by a court of equity... commanding the defendant to do or refrain from doing a particular act."
The common understanding captures the prohibitory side well but consistently underweights the mandatory injunction — orders compelling affirmative action. Researchers working in equity, civil rights, or administrative law will encounter mandatory injunctions frequently; treating all injunctions as stop-orders will cause misreading.
Core Elements
Courts applying the standard four-factor test — most clearly articulated in federal practice — require a party seeking a preliminary injunction to demonstrate:
1. Likelihood of success on the merits: The moving party must show a meaningful probability of prevailing, not merely a colorable claim.
2. Likelihood of irreparable harm absent relief: The harm must be one that money damages cannot adequately remedy. This is the conceptual heart of equity jurisdiction.
3. Balance of equities: The hardship to the moving party if relief is denied must outweigh the hardship to the opposing party if relief is granted.
4. Public interest: The injunction must not be adverse to the broader public interest.
Note that courts have varied in whether these factors must all be met or whether they can be weighed on a sliding scale. Researchers should not assume uniform application across circuits or state systems.
Why It Matters in Research
The historical legal dictionary entries provided for this term are a mismatch: both Black's and Rapalje & Lawrence describe an "injunction officer" — a now-abolished officer of the English Court of Chancery — not the remedy itself. This is a known source hazard. Older dictionary editions sometimes filed procedural officers and instruments under the same root term, and researchers pulling entries by keyword alone may land on the officer entry rather than the remedy entry. Cross-check by edition and context.
The substantive law of injunctions evolved significantly across the nineteenth and twentieth centuries. Pre-merger equity practice (before the merger of law and equity in federal courts under the Federal Rules of Civil Procedure in 1938) treated injunctions as exclusively chancery remedies with distinct procedural rules. Post-merger, the mechanics changed but the equitable principles — adequate remedy at law, irreparable harm, clean hands — survived. Research in pre-1938 federal sources or in state systems that retained separate equity courts longer will encounter this procedural divide.
Jurisdictional traps are real. The preliminary injunction standard is not uniform. Some circuits historically applied a sliding-scale approach; others required threshold showings on each factor independently. State courts vary further. Research on injunctive practice in a specific jurisdiction requires checking that jurisdiction's governing standard, not importing federal four-factor doctrine wholesale.
In employment law, injunctions enforcing restrictive covenants (non-competes, non-solicitation clauses) carry additional layers: many states now disfavor or restrict enforcement by statute, and courts vary widely on whether to reform overbroad covenants rather than void them entirely. The injunction remedy in that context is inseparable from the underlying enforceability question.
Injunction bonds under Rule 65(c) are a connected but distinct research area. When a court issues a preliminary injunction or TRO, it typically requires the moving party to post security against wrongful injunction damages. Researchers analyzing injunction litigation must account for this financial mechanism, which affects both litigation strategy and available damages if the injunction is later found to have been improperly granted.
Historical Dictionary Support
Both Black's Law Dictionary and Rapalje & Lawrence, as sourced here, provide entries describing the injunction officer of the English Court of Chancery — an administrative role abolished by 15 & 16 Vict. c. 87, § 23 — rather than the remedy of injunction itself. This is a genuine editorial gap in the historical record as captured in these particular entries, not an error in the present dictionary. Researchers should not interpret the historical entries as evidence that "injunction" historically referred only to an officer; that reading would be badly wrong. The injunction as a judicial command has deep roots in equity practice predating and surviving the officer role entirely.
What the historical dictionaries miss entirely here is the substantive doctrine: the grounds for granting injunctions, the evolution of the irreparable harm requirement, the distinction between prohibitory and mandatory relief, and the procedural framework that modern practice inherited from chancery. Those gaps must be filled from treatise sources and case law.
Jurisdictional Note
Federal injunction practice is governed primarily by Rule 65 of the Federal Rules of Civil Procedure, with the substantive standard shaped by case law. State courts vary significantly in both procedure and the governing multi-factor test; some states codify injunction standards by statute. International and foreign law contexts may use the term interlocutory injunction or interim injunction for what U.S. practice calls a preliminary injunction.
Encyclopedia Cross-Reference
Injunction Bonds — Rule 65(c), Amount, and Wrongful Injunction Damages (The Law Mind Remedies & Equity Encyclopedia)
Remedies — Injunctive Relief in Contract Disputes (The Law Mind Contracts & Commercial Law Encyclopedia)
Injunctive Relief and Enforcement of Restrictive Covenants (The Law Mind Employment & Labor Law Encyclopedia)