Definition
Accessory carries two distinct legal meanings that share a common conceptual thread — something secondary, subordinate, or ancillary to a principal thing.
1. PROPERTY AND CONTRACT LAW: An accessory is a thing joined to or accompanying another thing as an incident or subordinate element, serving to complete, ornament, or accompany the principal thing. The accessory follows the principal: when the principal thing is transferred, sold, or bequeathed, the accessory generally passes with it unless expressly excluded. Examples include the halter of a horse, the frame of a picture, or the keys of a house.
2. CRIMINAL LAW: An accessory is a person who participates in a crime without being the principal actor — one who aids, assists, or contributes to a criminal act in a secondary capacity. This meaning is distinct from, and frequently confused with, the spelling variant "accessary," which the historical sources treat as the preferred spelling in the criminal context. The two spellings refer to the same legal concept. For the full doctrinal treatment of criminal accessories — including the before/after distinction, the mental state required, and the relationship to principals — see the entry for ACCESSARY and the encyclopedia entry referenced above.
Common Language
Modern common usage (Wiktionary): Having a secondary, supplementary, or subordinate function; aiding in a secondary way; assisting a crime without actually participating in committing the crime itself; present in a minor amount and not essential.
Historical common usage (Webster's 1913): Accompanying as a subordinate; aiding in a secondary way; additional; connected as an incident or subordinate to a principal; contributing or contributory — said of persons and things, and when of persons, usually in a bad sense.
The gap between common and legal usage is narrower here than with many legal terms — both track the core idea of subordinate accompaniment. The meaningful divergence is practical: ordinary usage (fashion accessories, automobile accessories) applies the property-law sense casually, while criminal-law usage carries precise doctrinal consequences about liability, charging, and punishment that the common definition does not capture.
Common Confusion
ACCESSORY VS. ACCESSARY
Historical dictionaries consistently flag that "accessary" is the preferred spelling in criminal law, while "accessory" is used more broadly for the property/contract sense. In modern practice, both spellings appear interchangeably in criminal contexts, and most contemporary sources treat them as identical. Researchers in historical sources should not assume a distinction in substance when they encounter differing spellings — but should be alert to the fact that an older text using "accessory" in a criminal-law discussion may be directing them to a separate headword ("accessary") for the full doctrine.
Recognized Forms
/SUBTYPES
In the criminal law sense, accessories are traditionally divided into:
- Accessory before the fact: one who counsels, procures, or commands the commission of a crime but is not present at its execution.
- Accessory after the fact: one who, knowing a felony has been committed, receives, relieves, comforts, or assists the felon to avoid arrest or punishment.
These subtypes are treated at length under ACCESSARY and in the encyclopedia entry.
Why It Matters in Research
The primary research trap with this term is the spelling split. Historical sources — including both editions of Black's represented here — consistently state that "accessary" is the preferred spelling for the criminal-law concept and cross-reference that headword. A researcher searching only "accessory" in a historical corpus may miss substantive criminal-law doctrine filed under "accessary." Both spellings should be queried when working in pre-twentieth-century legal materials.
In the property and contract sense, the accessory doctrine connects directly to the law of accession, fixtures, and sale of property. The principle that accessories follow the principal has practical consequences in conveyancing, probate, and commercial transactions. Bouvier's example — that the sale of a newspaper establishment carries its subscription list as an accessory — illustrates how courts applied this principle to intangible and mixed assets, a point relevant to researchers examining early commercial or intellectual property disputes.
The term "accessorial" appears in some sources (notably Anderson's and Story's Bailments via Burrill) as an adjectival form covering both senses. Researchers should treat "accessorial obligation" and "accessorial service" as signals that the text is operating in the subordinate/accompanying framework, not necessarily the criminal one.
Jurisdictional variation in the criminal sense — including the abolition of the before/after distinction in some modern statutes and its merger into accomplice liability — is addressed under ACCESSARY.
Historical Dictionary Support
The historical sources show strong agreement on the property-law definition and consistent redirection on the criminal-law definition. Black's (both editions) and Anderson's give nearly identical formulations: a thing joined to another as an ornament or incident, subordinate to the principal. Both Black's editions then pivot to the criminal sense with a one-line cross-reference: "In criminal law. An accessary. The latter spelling is preferred." This explicit redirect is a deliberate structural choice, not casual variation.
Bouvier's develops the property-law sense most fully, providing concrete examples (halter, picture frame, house keys) and citing authority for the subscription-list principle. Bouvier does not attempt to cover the criminal meaning under this headword, consistent with treating "accessary" as the controlling criminal-law entry.
Burrill takes the most jurisprudential approach, citing Finch's Law and Wingate's Maxims for the principle that "things accessory are of the nature of the principal" — grounding the property doctrine in the broader maxim that the accessory follows and shares the nature of the principal thing. Burrill also notes Story's Bailments for the "accessorial" adjectival usage.
Anderson's is the only source to enumerate discrete sub-meanings in numbered form, distinguishing the adjectival sense (accompanying, incidental), the property sense (an incident or subordinate thing), and the criminal sense as a separate item — the clearest structural separation among the shelf sources.
No source in this corpus develops the criminal-law doctrine under this headword; all treat that discussion as belonging to "accessary."