Definition
A Latin term meaning, literally, a running or course. In legal usage, CURSUS carries two distinct senses:
1. A physical course or channel — most commonly the course of a watercourse (cursus aquæ), referring to the natural path or flow of a stream or river as it bears on questions of riparian rights, boundary disputes, and property descriptions in old conveyances.
2. The practice or customary procedure of a court — as in the maxim cursus curiæ est lex curiæ (the practice of a court is the law of the court). In this sense, cursus denotes the established, inveterate procedural usage of a particular tribunal, which that court treats as binding on itself in the absence of contrary authority.
A third, narrower usage appears in old English mining law: cursus carbonum, a seam or course of coal, appearing in pleading and conveyancing connected with subsurface mineral rights.
Common Language
Modern common usage (Wiktionary): A course; a journey or progression. Also: a Neolithic earthwork of unknown function; a racecourse; an academic curriculum; a form of daily prayer or service.
Historical common usage (Webster's 1913): Not separately entered; subsumed under general Latin borrowings relating to running or course.
The legal sense of cursus as established court practice diverges sharply from any of its common meanings. A reader encountering cursus in a modern context would most naturally reach for the academic or liturgical sense; a reader of old English legal materials must recognize that the term functions as a term of art for procedural custom with normative force — closer in effect to what modern lawyers call "local rules" or "court practice" than to any ordinary notion of a course or path.
Common Confusion
Cursus as procedural practice is sometimes conflated with lex curiæ (law of the court) as though they were synonymous expressions. They are not. Cursus curiæ describes the empirical fact of habitual court usage; lex curiæ is the normative claim — that such usage has the force of law within that court. The maxim cursus curiæ est lex curiæ connects the two: the practice (cursus) is elevated to law (lex) by virtue of its establishment and consistency. Treating cursus alone as meaning "law of the court" collapses a distinction the maxim itself preserves.
Why It Matters in Research
Researchers working in equity records, Chancery proceedings, or early common law pleading will encounter cursus most frequently in the procedural sense. The maxim cursus curiæ est lex curiæ was a standard justification for courts — especially courts of equity — to follow their own settled procedures without explicit rule or statute. Anderson's note that a court of error does not generally take notice of the practice of another court is a practical caution: the cursus of Chancery did not bind King's Bench, and vice versa. When tracing procedural arguments across courts or across time, a researcher cannot assume that a cursus established in one tribunal carries weight in another.
For property and water law researchers, cursus aquæ appears in boundary descriptions, riparian disputes, and drainage controversies well into the nineteenth century. The phrase fixes the natural channel as the legally significant line, and its appearance in a deed or pleading should prompt investigation of the watercourse's historical path — which may have shifted — rather than its current one.
Cursus carbonum is rare but significant in the context of mining conveyances and subsurface rights disputes in English law. Burrill's citation to Townshend's Pleader points researchers toward the technical pleading tradition surrounding mineral grants.
The term is almost entirely absent from American legal usage except in historical materials and Latin maxim collections. Researchers using those collections should be alert to the possibility that American courts citing the cursus curiæ maxim were borrowing English equity practice without necessarily committing to its full doctrinal weight.
Historical Dictionary Support
Anderson and Burrill are in close agreement on the core meanings. Both identify the procedural sense (cursus curiæ) as the primary legal usage and both reproduce the maxim cursus curiæ est lex curiæ with similar glosses. Anderson expands the practical implication — noting that established practice is presumed to rest on justice and public convenience, but that appellate courts do not generally audit the practice of inferior courts — which Burrill leaves undeveloped. Burrill adds the watercourse and coal-seam senses that Anderson omits, making Burrill the more comprehensive source for property-side uses of the term.
Neither dictionary engages with the theoretical tension in the maxim: if a court's own practice is its own law, the doctrine is self-referentially closed in ways that invite abuse. That critique is absent from both historical sources and belongs instead to the commentary tradition on judicial procedural authority.
Jurisdictional Note
Cursus as a legal term of art is essentially a feature of English legal history and equity practice. American jurisdictions adopted elements of the underlying principle — that courts may establish and enforce their own procedural customs — but rarely used the Latin term. Researchers in Scottish, Irish, or Commonwealth legal materials may encounter it in contexts shaped by their own equity traditions, which diverged from English Chancery practice in important respects.