Definition
A clause is a discrete unit of a written legal instrument — a single paragraph, subdivision, sentence, or part of a sentence — that performs a defined function within the larger document. Clauses appear in contracts, deeds, wills, statutes, constitutions, treaties, and other formal legal writings. They are the building blocks of legal drafting: each clause typically expresses one operative rule, condition, limitation, or grant.
In statutory drafting, a clause may carry a specialized role. A definition clause (sometimes called an interpretation clause or dictionary clause) gathers the meanings assigned to terms used throughout the statute. An enacting clause signals the formal exercise of legislative authority. Other clauses — penal, residuary, sweeping, guaranty, commerce — take their names from the substantive work they perform.
In contract law, clauses define rights, allocate risk, limit liability, specify remedies, or preserve the instrument's integrity (as with integration or merger clauses). In constitutional law, individual clauses carry enormous independent legal weight — the Commerce Clause, the Supremacy Clause, and the Takings Clause, for example, are each treated as self-contained legal commands.
Common Language
Modern common usage (Wiktionary): To amend a bill of lading or similar document — a narrow, specialized shipping-industry usage.
Historical common usage (Webster's 1913): A separate portion of a written paper, paragraph, or sentence; an article, stipulation, or proviso in a legal document; or, in grammar, a subordinate portion of a sentence containing a subject and its predicate.
The Webster's definition sits close to legal usage, but the Wiktionary entry reveals a divergence worth flagging: in shipping and trade practice, "to clause" functions as a verb meaning to mark or annotate a transport document (typically a bill of lading) to indicate that cargo was received in less than perfect condition. A "claused" bill of lading — also called a "foul" bill — is distinct from a "clean" bill of lading and carries significant consequences in trade finance. A researcher encountering "clause" as a verb in commercial documents should not assume the standard documentary meaning applies.
Recognized Forms
/SUBTYPES
Clauses take their names from their function. Among those most frequently encountered in legal research:
Commerce Clause — the constitutional grant to Congress to regulate interstate and foreign commerce; one of the most litigated clauses in American constitutional history.
Definition/Interpretation/Dictionary Clause — appears in statutes and complex contracts to fix the meaning of terms used throughout the instrument.
Enacting Clause — the formal words by which a legislature brings a statute into effect; typically "Be it enacted by..."
Integration/Merger Clause — in contracts, declares the written document to be the complete and final expression of the parties' agreement, limiting resort to extrinsic evidence.
No Oral Modification Clause — specifies that the agreement may only be amended in writing.
Penal Clause — imposes a specified penalty for breach or non-performance.
Residuary Clause — in a will, sweeps up all property not otherwise disposed of by specific bequest.
Sweeping/General Clause — a catch-all provision intended to extend the reach of a statute or instrument beyond its enumerated items.
Accruer Clause — in instruments creating concurrent interests, provides that a failed share passes to surviving co-owners rather than lapsing.
Clause Irritant — in Scots law, a provision that voids acts done in contravention of the instrument's terms; paired with a resolutive clause that terminates the offending party's rights.
Why It Matters in Research
The word "clause" is both a structural descriptor and a term of art, and the two uses appear side by side throughout the corpus without always being distinguished. A researcher working in constitutional law will encounter specific named clauses treated as independent legal doctrines; a researcher in contracts will find clauses analyzed for their internal logic and interaction with other provisions; a researcher in statutory interpretation will encounter clauses parsed for their grammatical relationship to surrounding text.
Three research traps deserve attention:
First, named constitutional clauses are not uniformly named across time. What is now routinely called the "Commerce Clause" or the "Due Process Clause" may appear in older sources — and in the original instrument — simply as a clause within a section, without a proper-noun label. Searching only for the modern name will miss early interpretive materials.
Second, interpretation clauses in statutes have changed in function. Early statutes used interpretation clauses narrowly; modern drafting practice has expanded definition sections into lengthy stand-alone articles. A researcher tracing the meaning of a statutory term must determine whether the definition in an interpretation clause was present in the version of the statute applicable to the dispute.
Third, "clause" in historical English law documents may signal a connection to the close rolls (clause rolls), which recorded royal grants and writs issued under the great seal in closed (as opposed to patent, or open) form. Burrill's entry on this point is a useful reminder that the term carried administrative and documentary meaning well beyond its use in private instruments.
Researchers in contract interpretation should note the tight corpus connection between clause analysis and the parol evidence rule. Integration clauses, merger clauses, and no oral modification clauses are frequently the dispositive issue in contract disputes, and their treatment varies enough by jurisdiction and time period that corpus research must be scoped carefully.
Historical Dictionary Support
The historical dictionaries are broadly consistent: a clause is a part of a written instrument, whether a sentence or subdivision of one. Black's (both editions), Bouvier's, and Anderson's all converge on this functional definition. Anderson's is the most practically useful of the group, expressly noting that clauses take their names from the nature of the provision they contain and listing the major recognized types — a list that remains largely accurate in modern practice.
Burrill's adds the most historically distinctive material, distinguishing between the Latin roots clausula (a part of a written instrument) and clausi/clausa (the old English close/patent distinction), and connecting clause rolls to the close rolls of the English royal administration. This cross-reference to Clausum and Close enriches research into medieval and early modern English legal documents and explains why "clause" and "close" share etymological space in early sources.
Black's second edition adds case citations (Appeal of Miles; Eschbach v. Collins) supporting the basic definition, and includes the Scots law clause irritant as a recognized subtype — a reminder that Scots private law terminology occasionally appears in older American and British treatises and should not be confused with common law doctrine.
What the historical dictionaries do not address: constitutional clause doctrine as an independent field of legal analysis, the integration clause as a contract drafting tool, and the modern bill-of-lading usage. These are twentieth and twenty-first century developments largely absent from the shelf sources.
Jurisdictional Note
Named constitutional clauses operate exclusively at the federal level or within state constitutional equivalents, and their interpretation is jurisdiction-specific. Contract clause doctrine — including the enforceability of integration, merger, and no oral modification clauses — varies by state, particularly on the question of whether course of dealing or conduct can override a written integration clause.
Encyclopedia Cross-Reference
Contracts & Commercial Law Encyclopedia — Interpretation: Integration Clauses, Merger Clauses, and No Oral Modification Clauses (contracts_48)