Definition
To regulate means to control, direct, or govern conduct, activity, or a subject matter through rules, laws, or authoritative standards. In legal usage, the term operates at several levels of specificity depending on context:
1. As a general legal verb: To regulate is to impose binding requirements on persons, entities, or activities — prescribing what may be done, how it must be done, when it is permitted, and under what conditions. Regulation may restrict, require, license, or set standards for behavior without necessarily prohibiting it outright.
2. In constitutional law (Commerce Clause): To regulate commerce is to prescribe the rules by which commercial activity is governed — including the conditions of its conduct, the duties or exactions to which it is subject, and control over the instrumentalities and means by which commerce is carried on. This meaning, developed through Commerce Clause jurisprudence, is broader than ordinary direction: it encompasses the full range of congressional authority to structure the terms and conditions of interstate commercial activity.
3. In administrative law: To regulate describes the ongoing exercise of authority by a governmental agency — including rulemaking, licensing, inspection, enforcement, and standard-setting — over a defined subject matter or industry.
Common Language
Modern common usage (Wiktionary): To control or direct according to rule, principle, or law; to put or maintain in order; to adjust a mechanism for accurate functioning.
Historical common usage (Webster's 1913): To adjust by rule, method, or established mode; to direct by rule or restriction; to subject to governing principles or laws; to put in good order.
The common meaning is not far from the legal meaning, but the gap is significant in one direction: in ordinary usage, "regulate" often implies modest adjustment or oversight. In constitutional and administrative law, the power to regulate is an affirmative, sweeping grant of authority — encompassing prohibition, compulsion, licensing, and structural control. A researcher reading "regulate" in a constitutional text or agency enabling statute should not read it as mere fine-tuning.
Common Confusion
"Regulate" is sometimes conflated with "prohibit." Courts have at times treated the two as distinct — the argument being that a power to regulate does not include the power to ban entirely. This debate arises acutely under the Commerce Clause and the Second Amendment. The distinction is not settled uniformly and varies by constitutional provision and subject matter. Researchers should not assume that a regulatory power necessarily authorizes outright prohibition, nor that it necessarily excludes it.
Why It Matters in Research
The constitutional meaning of "regulate" is a major research target in itself. Commerce Clause materials spanning from the nineteenth century through the twentieth century show dramatic evolution in what Congress could reach under the power to "regulate Commerce among the several States." Sources from before the New Deal era reflect a narrower understanding; post-1937 materials reflect a much broader one. Researchers working with pre-New Deal materials must account for this interpretive gap — the word "regulate" in an 1890 treatise carries different operative scope than the same word in a 1970 administrative law context.
In administrative law materials, "regulate" often appears in organic statutes defining an agency's jurisdiction. Whether the term grants authority to act in a particular way — through adjudication versus rulemaking, for example — is frequently litigated. The word alone does not answer those questions; the surrounding statutory structure matters.
Historical sources in the Law Mind corpus use "regulate" both in the narrow mechanical sense (adjusting, ordering) and in the broad constitutional sense, sometimes without distinguishing between them. Bouvier's entry is purely definitional and tracks the common meaning closely; the Black's entries jump directly to the Commerce Clause application without engaging the general meaning. Neither source gives a complete picture of the term's legal range.
Researchers should also note that "regulate" in older materials may appear in contexts — such as militia regulation, the regulation of religious orders, or the regulation of weights and measures — that have little bearing on modern administrative or Commerce Clause research. Filtering by subject-matter context is essential.
Historical Dictionary Support
Bouvier's defines "regulate" in a general and non-technical way: to adjust by rule, method, or established mode; to direct by rule or restriction; to subject to governing principles or laws. This tracks the common meaning precisely and offers no constitutional dimension.
Both editions of Black's skip the general definition almost entirely and move directly to the Commerce Clause, defining the regulatory power as the authority to prescribe rules governing commerce — including its conditions, freedom, duties, instrumentalities, and means. The two editions are substantively identical on this point, reflecting the settled understanding of the term in constitutional jurisprudence at the time of publication.
What none of the historical sources address is the administrative law dimension — regulation by agency, rulemaking authority, or delegated regulatory power. That entire framework developed largely in the twentieth century and falls outside the coverage period of these dictionaries. Researchers relying on these sources for modern administrative law questions will find them incomplete.
Jurisdictional Note
The constitutional meaning of "regulate" in the Commerce Clause context is a matter of federal constitutional law and applies uniformly across jurisdictions, though the precise limits of congressional regulatory power remain contested at the margins. State police power to "regulate" health, safety, and welfare operates on a parallel track and is governed by state constitutional and statutory law, which varies considerably.
Encyclopedia Cross-Reference
Business Organizations & Corporate Law Encyclopedia: International Securities Regulation (Regulation S, ADRs) — for the application of regulatory authority in cross-border securities contexts.