Definition
Infringement is the unauthorized violation of a legally protected right. In modern usage the term appears most frequently in intellectual property law, where it denotes the unauthorized making, using, selling, or distribution of material or processes protected by patent, copyright, or trademark. More broadly, it can describe any breach of a legal duty, regulation, or contract right.
Three principal meanings operate in legal research:
1. Intellectual Property Infringement. The core modern sense. An actor who, without license or other legal authority, exercises a right belonging exclusively to the rights-holder — reproducing a copyrighted work, manufacturing a patented device, or deploying a registered mark in commerce — commits infringement. Each IP regime defines the act differently, and each supplies its own remedies.
2. General Rights Infringement. A broader usage: any encroachment upon a legally recognized right, including constitutional rights (e.g., infringement of the right to bear arms) or common-law rights. Courts and statutes use the word in this broader sense when the specific IP context is absent.
3. Contractual/Regulatory Violation. An older and now less common usage treats infringement as a synonym for breach — violation of a treaty, compact, statute, or regulation. This sense appears frequently in historical sources and is still encountered in specialized regulatory contexts.
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Common Language
Modern common usage (Wiktionary): A violation or breach, as of a law; an encroachment on a right, a person, a territory, or property.
Historical common usage (Webster's 1913): The act of infringing; breach, violation, nonfulfillment — as of a treaty, compact, law, or constitution; also, an encroachment on a patent, copyright, or other special privilege.
The gap between common and legal meaning is modest but consequential in one direction: ordinary English treats infringement as a general synonym for violation or encroachment. Legal usage has progressively concentrated the term in intellectual property, where it carries technical meaning — specific acts, specific defenses, specific statutory remedies — that distinguishes it sharply from a mere "breach." A researcher who encounters "infringement" in a non-IP legal source must check whether the author means the technical IP sense, the constitutional-rights sense, or simply the older general-breach sense.
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Common Confusion
INFRINGEMENT vs. BREACH. In contract law, the correct term for failure to perform is breach, not infringement. Historically the two overlapped; Anderson's and Webster's both list breach as a near-synonym. Modern usage has separated them almost entirely: infringement belongs to IP and rights-violation contexts; breach belongs to contract. Encountering "infringement of a contract" in older sources signals the historical usage, not a distinct legal concept.
DIRECT vs. CONTRIBUTORY vs. VICARIOUS INFRINGEMENT. These three liability theories are all called "infringement" but rest on entirely different legal foundations. Direct infringement requires no knowledge or intent. Contributory infringement — flagged in Black's 2nd Ed. — requires knowledge of the infringing activity and a material contribution to it. Vicarious infringement requires the ability to supervise the direct infringer and a financial interest in the infringing activity. Treating them interchangeably is a persistent research error.
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Core Elements
Because infringement doctrine varies by IP type, the operative elements differ by regime. The common structural question across all three is:
1. Valid, enforceable right. The plaintiff must hold a right the law recognizes and protects (a valid patent, subsisting copyright, protectable mark).
2. Unauthorized act. The defendant performed an act falling within the exclusive rights granted to the holder, without license or legal excuse.
3. Correspondence or substantial similarity. The defendant's act must correspond to the protected subject matter — by identity, substantial similarity (copyright), equivalence (patent doctrine of equivalents), or likelihood of confusion (trademark).
Intent is generally not an element of direct infringement in any of the three regimes, though it bears on damages and willfulness.
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Recognized Forms
/SUBTYPES
Direct Infringement. Personal commission of an infringing act without authorization. Strict liability in most IP contexts; intent is irrelevant to liability.
Contributory Infringement. Knowing participation in or material contribution to another's direct infringement. Recognized in patent and copyright law.
Vicarious Infringement. Liability arising from the right and ability to supervise a direct infringer combined with a direct financial interest in the infringement. Principally a copyright doctrine.
Induced Infringement. Actively encouraging or instructing another to infringe. Codified in patent law.
Literal Infringement. In patent law, the accused device or process falls squarely within the claim language word for word.
Infringement Under the Doctrine of Equivalents. The accused device or process does not literally satisfy the claim but performs substantially the same function in substantially the same way to achieve substantially the same result.
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Why It Matters in Research
The term's historical promiscuity is the primary trap. Pre-twentieth-century sources use infringement freely for any kind of legal violation. A researcher mining Bouvier, Anderson, or early federal reporters for patent or copyright doctrine will encounter the word in its precise IP sense, but a researcher working on constitutional law, regulatory history, or contract sources from the same period will find it used loosely for breach or encroachment. Context must govern interpretation.
The IP specialization sharpened considerably in the late nineteenth and early twentieth centuries as patent and copyright litigation exploded in the federal courts. Bouvier's entries reflect this transition clearly: the patent-law entries are dense with early federal circuit authority; the general entry still preserves the older broad meaning alongside it. Black's 1st and 2nd Ed. reflect the same dual awareness but signal, through their parenthetical cross-references to contributory infringement, that specialized doctrine was already ramifying.
Jurisdictional and doctrinal evolution matters most in patent law. The doctrine of equivalents — directly addressed in Bouvier's entries on "substantially the same way" — has been constrained and reshaped repeatedly. Historical research on what constitutes infringement in patent cases must account for this evolution; relying on pre-twentieth-century doctrine about equivalents without checking subsequent development will produce unreliable results.
Trademark infringement in historical sources is less developed than its patent and copyright counterparts. Rapalje & Lawrence treats it almost as an afterthought alongside patent and copyright. Researchers tracing trademark infringement doctrine should expect thinner historical dictionary support and rely more heavily on case law.
The encyclopedia entry ip_73 addresses the multi-factor likelihood-of-confusion test that defines trademark infringement in modern law — a doctrinal structure entirely absent from historical dictionaries, which confirms that historical sources alone are insufficient for trademark infringement research.
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Historical Dictionary Support
The historical dictionaries converge on the core definition: infringement is an unauthorized encroachment on a legally protected right, especially in patent, copyright, and trademark contexts. All five sources reflect this. The divergence lies in breadth: Anderson's expressly preserves the general sense (violation of law, regulation, contract) alongside the technical IP sense and notes that the IP usage had become "almost technical" — a useful period marker for when the term began narrowing.
Bouvier's is the most analytically useful historical source for patent infringement specifically. It distinguishes literal infringement from infringement by equivalent operation, addresses combination patents, and cites early federal circuit authority throughout. Researchers will find Bouvier's patent-law entries more granular than Black's, though neither addresses the constitutional dimensions of patent scope or the doctrine-of-equivalents constraints that developed through the twentieth century.
Black's 2nd Ed. is notable for flagging contributory infringement by name — an early dictionary recognition of a doctrine that would become central to copyright and patent litigation in the digital era. Neither Rapalje & Lawrence nor Anderson's develops this concept.
What the historical sources miss collectively: the statutory codification of the exclusive rights at issue (particularly the Copyright Act and Patent Act as revised and reenacted across the twentieth century), the fair use doctrine in copyright, the doctrine of patent exhaustion, and the multi-factor tests now governing trademark infringement. Historical dictionaries supply the conceptual frame; they do not supply modern doctrine.
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Jurisdictional Note
Patent and copyright infringement are exclusively federal questions governed by federal statute; state law is preempted. Trademark infringement has both federal (Lanham Act) and state common-law dimensions, and state unfair competition claims can overlap substantially with trademark infringement claims. Researchers working on trademark infringement must determine whether the claim is federal, state, or both.
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Encyclopedia Cross-Reference
ip_73: Trademark Infringement — Likelihood of Confusion and Multi-Factor Tests (The Law Mind Intellectual Property Encyclopedia)
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