Definition
A precarium is a civil law arrangement in which an owner allows another person to use a thing or exercise a right gratuitously, revocable at the owner's will at any time. The arrangement arises from a request or entreaty by the recipient — the name derives from the Latin for "obtained by prayer" — and the owner retains the absolute right to reclaim the thing whenever desired, regardless of whether a period of use was contemplated or even expressly promised. No exchange of consideration is required, and the grant confers no permanent or enforceable entitlement on the recipient.
The precarium occupies an unusual position in property and bailment law: the recipient obtains lawful possession of the thing for most purposes, yet holds it on a tenure more fragile than any contractual loan. The owner's right of revocation is not subject to estoppel or limitation based on the recipient's reliance or expectations.
In its land tenure application, the precarium describes a grant of land use or occupation made at the grantor's pleasure, with the grantee acquiring no title and remaining subject to immediate displacement upon demand.
Common Language
Modern common usage (Wiktionary): A form of land tenure in which a petitioner receives a property for a specific amount of time without any change of ownership.
Historical common usage (Webster's 1913): Not separately defined as an English word; treated as a Latin legal term carried into English legal usage.
The Wiktionary definition introduces a phrase — "for a specific amount of time" — that can mislead. The legal force of the precarium is precisely that the duration is irrelevant to the owner's power of revocation. Even where a period is named, the owner may still reclaim the thing at will. The common-language gloss understates the precariousness that is the arrangement's defining characteristic.
Common Confusion
Precarium is frequently conflated with commodatum — the ordinary gratuitous loan of civil law. The distinction matters. In a commodatum, the lender agrees to allow use for a specific purpose or period, and the borrower's obligations and rights during that period are fixed and legally enforceable. In a precarium, the owner's consent is ongoing and always withdrawable; there is no binding commitment of duration. Rapalje & Lawrence specifically flag this distinction, noting the different obligations the Roman law imposed on the borrower under each arrangement. Researchers encountering either term in historical sources should not treat them as interchangeable.
Why It Matters in Research
Precarium appears in historical legal texts primarily in civil law and Roman law contexts, making it most relevant to researchers working in Louisiana law, civilian treatise literature, comparative law materials, and colonial-era property records from jurisdictions influenced by Spanish or French law. In common law jurisdictions, the concept surfaces indirectly — courts describing licenses, tenancies at will, and gratuitous bailments sometimes engage reasoning that parallels precarium doctrine without using the term.
The critical research trap is anachronism: post-medieval English common law largely absorbed precarium-like arrangements into its own categories of tenancy at will and bare license, so the term itself disappears from English-language case law while the underlying structure persists. A researcher encountering precarium in a 19th-century Louisiana or civilian-influenced treatise is reading a living legal category; the same researcher encountering it in a common law jurisdiction context is more likely reading a scholarly or comparative gloss.
Burrill's reference to jus precarium is a useful pointer: that companion term describes the right itself as opposed to the arrangement, and tracing both terms together will yield fuller coverage in older Latin-language sources and early modern civilian digests.
Story's Bailments (cited by Rapalje & Lawrence at §§ 227 and 253b) is the most accessible English-language bridge between the Roman law precarium and 19th-century American bailment analysis, and researchers should consult it when civilian sources are unavailable.
Historical Dictionary Support
All five source dictionaries treat precarium as a Roman civil law institution and agree on its core features: gratuitous use, revocability at the owner's will, and a possessory interest in the recipient short of ownership. The definitions are largely harmonious.
Black's (both editions) draws on Mackeld's Roman Law for the proposition that the bailee acquires lawful possession "except in certain cases" — a qualification left unexplained in the dictionary entry but significant in depth research, as it reflects the Roman jurists' nuanced debate about whether precarium created true possession or merely detention.
Anderson's brief definition — "a thing held by entreaty, at the will of another" — emphasizes the informal, request-based origin most economically and captures the social texture of the arrangement, which was historically associated with grants from patrons to clients in Roman practice.
Burrill alone directs the reader to jus precarium, providing the most useful onward research pointer among the five dictionaries. Burrill also notes the Latin etymological root (precari, to pray), which helps explain why precarity and precarious derive from the same legal concept.
What the historical dictionaries collectively underemphasize is the arrangement's practical role in land tenure, particularly in medieval and early modern European law where precarium was used to document conditional occupancy of church lands and feudal grants — a context that surfaces in the Wiktionary definition but is absent from the standard legal dictionaries.
Jurisdictional Note
Precarium as a formal legal category is operative today primarily in civil law systems and mixed jurisdictions, especially Louisiana, Quebec, and Scottish law. In pure common law jurisdictions, courts and treatise writers have largely replaced it with tenancy at will, bare license, or gratuitous bailment, though civilian scholars continue to use the term in comparative analysis.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Bailment; Tenancy at Will; Jus Precarium; Civil Law Property Concepts.