Definition
ARMS has two principal legal meanings that operate in largely separate doctrinal contexts:
1. Weapons generally. In its broadest legal sense, arms means anything a person wears for defense, holds in the hand, or uses to cast at or strike another. This is the older common-law formulation, drawn from Coke and repeated across the historical dictionaries. It encompasses both offensive and defensive instruments and is not limited to firearms.
2. Arms in the constitutional sense. As used in the Second Amendment to the U.S. Constitution — "the right of the people to keep and bear Arms" — the term carries a more specific meaning developed through case law. Historically, the word was read in a military sense, referring to the weapons of an infantry soldier or militiaman. Modern constitutional doctrine, most prominently since District of Columbia v. Heller (2008), has shifted the interpretive center: the Supreme Court held that "arms" in the Second Amendment extends to weapons in common use for lawful purposes, including self-defense, and is not confined to militia service. The constitutional meaning of the term is now among the most actively litigated questions in American public law.
3. Heraldic arms. In the law of heraldry and, historically, in English property and peerage law, "arms" refers to the ensigns armorial of a family — the visual emblems displayed on an escutcheon according to heraldic rules. This meaning appears in older English legal materials and remains relevant in jurisdictions that retain formal heraldic law (principally Scotland and England), but is rarely encountered in American legal research.
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Common Language
Modern common usage (Wiktionary): Weaponry or weapons generally; also, a visual heraldic design displayed on an escutcheon.
Historical common usage (Webster's 1913): Instruments or weapons of offense or defense; the deeds or exploits of war; military service or science; also the ensigns armorial of a family or person.
The gap between common and legal meaning is sharpest in the constitutional context. Ordinary usage treats "arms" as synonymous with weapons of any kind. The legal debate turns on which weapons qualify for constitutional protection — a question ordinary usage does not answer and that the historical dictionaries, written before modern firearms regulation, could not anticipate.
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Common Confusion
Two confusions recur in research:
First, the shift from militia-centered to individual-rights interpretation. Pre-Heller sources — including standard legal dictionaries through most of the twentieth century — consistently described the constitutional meaning of "arms" in terms of the militia or soldier. Researchers encountering these sources should not read them as settling the current constitutional framework, which has been substantially revised.
Second, conflation of "arms" with "firearms." The legal definition of arms has always been broader than firearms alone. Knives, clubs, and other weapons fall within the common-law definition. Whether non-firearm weapons receive Second Amendment protection is a live doctrinal question; do not assume that "arms" and "guns" are coextensive in legal sources.
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Recognized Forms
/SUBTYPES
Bearing arms: The act of carrying weapons, particularly in a military or self-defense capacity. The phrase "keep and bear arms" in the Second Amendment treats keeping (possession) and bearing (carrying) as distinct but related rights.
Coat of arms / heraldic arms: The armorial bearings of a family or individual, governed by distinct rules of heraldic law. Essentially a separate legal domain from the weapons sense.
Small arms: A legislative and regulatory term of art referring to portable firearms and their components. Appears frequently in federal statutes and international arms control instruments.
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Why It Matters in Research
The constitutional dimension of this term is a moving target. The law governing what "arms" means for Second Amendment purposes has changed more dramatically in the last two decades than in the previous two centuries. Black's Law Dictionary (1st and 2nd editions) reflect the militia-era reading; neither anticipates the individual-rights framework of Heller or its subsequent extensions. Researchers citing historical dictionary definitions in constitutional arguments should treat them as evidence of historical usage, not as statements of current doctrine.
Corpus navigation note: In the Law Mind constitutional encyclopedia, The Second Amendment — Individual Right to Bear Arms (Heller) covers the post-2008 doctrinal framework. The Right to Bear Arms and State Militia provides the essential historical counterpart — indispensable for understanding originalist arguments on both sides of the Heller debate. These two entries should be read together, not in isolation.
For criminal law research, the relevant inquiry shifts entirely. Here the question is usually whether a specific object qualifies as a "dangerous weapon" or "deadly weapon" under a given statute, or whether an offense qualifies as "armed" for sentencing enhancement purposes. The constitutional definition of arms does not govern these questions; statutory definitions control, and they vary substantially by jurisdiction. See Armed Robbery and Carjacking in the Criminal Law Encyclopedia for context on how "armed" is defined and applied in that setting.
Heraldic arms appear in older English equity cases involving inheritance, peerage, and grant of arms by the College of Heralds. American researchers rarely encounter this meaning, but it surfaces occasionally in trusts and estates matters touching English lineage or in historical property disputes. Do not conflate it with the weapons sense when reading older English materials.
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Historical Dictionary Support
The core common-law definition — anything a man wears for defense or uses to strike another — appears verbatim or nearly so in Black's (both editions), Bouvier's, and Burrill's, all tracing back to Coke's Institutes. There is strong unanimity among the historical sources on this foundational formulation.
Bouvier's makes the most substantive engagement with the Second Amendment, quoting the Amendment's text and noting the contested relationship between the right to bear arms and the existence of a well-regulated militia. Black's 2nd edition cites State v. Buzzard (4 Ark. 18) in support of the militia-oriented reading — illustrative of the interpretive orthodoxy that prevailed through most of American legal history. Neither Bouvier's nor Black's anticipates the individual-rights development that Heller later established.
Burrill's is terse, directing the reader to the Latin "arma" and to the entry on "force and arms" — useful for tracing the term's roots in pleading formulas (vi et armis) rather than constitutional analysis.
The Rapalje & Lawrence and Anderson's entries retrieved under this term are not responsive to "arms" as a weapons or constitutional concept; they appear to be mis-indexed fragments concerning pleading and arbitration. Researchers should not rely on those sources for this term.
What the historical dictionaries collectively miss: the regulatory dimension. None addresses the permissible scope of legislative restriction on arms — the question that now dominates Second Amendment litigation. For that, the dictionaries are silent, and case law must supply the analysis.
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Jurisdictional Note
The Second Amendment applies to the states through the Fourteenth Amendment (McDonald v. City of Chicago, 2010), but state constitutional provisions governing the right to bear arms vary considerably in their text and judicial interpretation. Some state constitutions provide broader protections than the federal baseline; a few impose explicit limitations. Researchers working on state-level firearms law should consult the applicable state constitutional provision independently of the federal framework.
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Encyclopedia Cross-Reference
The Second Amendment — Individual Right to Bear Arms (Heller) — The Law Mind Constitutional Law Encyclopedia
The Right to Bear Arms and State Militia (Historical Context of the Second Amendment) — The Law Mind Constitutional Law Encyclopedia
Armed Robbery and Carjacking — The Law Mind Criminal Law Encyclopedia
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