Definition
To disclose is to reveal, make known, or bring to light information that was previously hidden, withheld, or not apparent. In law, the term carries a range of operational meanings depending on context, but all share a common core: an affirmative act — or legally required omission of concealment — that puts information into the possession or awareness of another party.
1. Agency law. An agent discloses a principal by identifying who the principal is to a third party. The principal is "disclosed" when the third party knows both that the agent is acting on behalf of someone else and who that someone else is. A principal is "undisclosed" when the third party is unaware that an agency relationship exists at all. Whether disclosure has occurred determines the allocation of contractual liability between the agent and the principal.
2. Litigation and procedure. To disclose a defense is to open it for examination — to present it to a court with sufficient clarity that the court can assess whether a genuine legal defense exists. Anderson's frames this as "opening out and letting the judge see whether there really is a defense." Disclosure in this sense is not merely assertion; it implies substantive exposure of the defense's content.
3. Transactional and regulatory law. Parties to contracts, real estate transactions, securities offerings, and regulated industries are often required by statute, rule, or common law to disclose material information — facts that a reasonable party would consider significant in deciding whether and on what terms to proceed. Failure to disclose when a duty to disclose exists may constitute fraud, misrepresentation, or breach of fiduciary duty.
4. Discovery. In civil litigation, disclosure refers to the mandatory pre-trial sharing of information and documents between parties, either pursuant to court rules requiring automatic initial disclosures or in response to formal discovery requests.
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Common Language
Modern common usage (Wiktionary): Defined simply as "a disclosure" — the noun form foregrounded, the verb treated as self-explanatory.
Historical common usage (Webster's 1913): To unclose or open; specifically applied to hatching eggs (to bring forth by exposure to warmth); more broadly, to remove a cover or envelope from something; to lay open or expose to view.
The Webster's sense captures the everyday meaning cleanly — to uncover what was hidden. The legal meaning carries that core but adds a critical layer: in law, disclosure is often not merely permitted or incidental but mandatory. The legal question is rarely whether something was disclosed in the sense of becoming known; it is whether the disclosing party had a duty to disclose, whether that duty was satisfied, and what consequences attach to non-disclosure. The physical metaphor of uncovering obscures the normative weight that the legal term carries.
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Common Confusion
Disclose vs. Represent. Disclosure involves making information available or known; representation involves making an affirmative statement of fact. The distinction matters in misrepresentation claims. A party may have a duty to disclose a material fact without making any representation about it — silence can breach a duty to disclose but does not constitute a false representation. Conversely, an affirmative misrepresentation does not require that the speaker had a prior duty to speak at all.
Disclosed vs. Undisclosed Principal. These are technical terms of art in agency law that hinge entirely on what a third party knows at the time of contracting. Researchers should not conflate "undisclosed principal" with a principal who is merely unnamed or difficult to identify; the test is whether the third party is aware that an agency relationship exists, not whether the principal's identity is known in detail.
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Why It Matters in Research
Disclose is a high-frequency term across entirely different bodies of law — agency, real estate, securities, evidence, civil procedure — and it functions differently in each. Researchers must anchor the term to its legal context before treating any authority as relevant.
In historical sources, disclose appears most commonly in agency and pleading contexts. The Anderson's entry reflects this: disclosed and undisclosed principal doctrine was well developed in the common law long before modern statutory disclosure regimes emerged. Researchers tracing disclosure obligations in real estate or securities will find little useful material in 19th-century dictionary sources; those obligations are creatures of statute and regulation that developed primarily in the 20th century.
The duty-to-disclose question — as distinct from the act of disclosing — is often where legal disputes concentrate. Historical sources treat the act as the relevant legal event; modern law has significantly expanded inquiry into the antecedent duty. When researching failure-to-disclose claims, the threshold question of whether a duty existed is usually outcome-determinative and highly jurisdiction-specific.
In agency law, the disclosed/undisclosed distinction produces concrete effects on contract liability: a disclosed principal is directly bound; an agent who contracts on behalf of an undisclosed principal may be personally liable. This doctrine is stable and well-represented in historical dictionaries.
In real estate specifically, the connection between broker liability and the duty to disclose is a major area of modern litigation. The Law Mind encyclopedia entry on broker liability is the natural next stop for researchers working in that context.
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Historical Dictionary Support
Anderson's Dictionary of Law offers two useful anchor points. The first — disclosing a defense upon the merits as "opening out and letting the judge see whether there really is a defense" — captures an older procedural usage tied to the practice of demurrer and early pleading, where courts assessed whether the pleadings sufficiently exposed a cognizable legal defense. This usage is largely displaced in modern practice by notice pleading and procedural disclosure rules, but it surfaces in historical case research.
The second — the disclosed/undisclosed principal distinction in agency — is the more durable doctrinal entry. Anderson's correctly identifies this as a binary classification with legal consequences, and the cross-references to AGENT and AUCTIONEER signal the commercial contexts in which the distinction most frequently arose. The Anderson's entry does not address statutory disclosure duties, which is the expected limitation of a 19th-century source.
Historical dictionaries generally do not speak to the regulatory and transactional disclosure obligations that now dominate practice. Researchers should treat dictionary sources as useful for common-law foundations but look to statutory and regulatory materials for modern duty-to-disclose analysis.
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Jurisdictional Note
Statutory duties to disclose vary substantially by jurisdiction, particularly in real estate (seller disclosure requirements), securities (both federal and state blue-sky law), and consumer transactions. The common-law duty to disclose in contract and agency contexts is more uniform but still subject to local variation in scope. Federal civil procedure imposes automatic initial disclosure obligations under Rule 26; state procedural counterparts differ significantly.
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Encyclopedia Cross-Reference
Broker Liability — Negligence, Misrepresentation, and Failure to Disclose (Law Mind Real Estate Transactions & Construction Encyclopedia)
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