Definition
A Latin term appearing in old English law meaning "flow," specifically the flow of water — particularly tidal water. The term survives in legal sources almost exclusively through the phrase *per fluxum et refluxum maris* ("by the flow and reflow of the sea"), which was used to describe the extent of tidal reach as a boundary marker or legal limit. In this context, fluxus functioned as a descriptor of physical phenomena that carried legal consequences — chiefly in matters of foreshore rights, admiralty jurisdiction, and the demarcation of the king's dominion over tidal waters.
Common Language
Modern common usage (Wiktionary): An international movement of artists, poets, composers, and designers of the 1960s and 1970s, noted for experimental syntheses of different media and disciplines.
Historical common usage (Webster's 1913): Not independently listed. The Latin root *fluxus* was understood in general educated usage as meaning "flow" or "flux," a sense carried into English scientific and philosophical vocabulary.
The gap here is total rather than partial. A researcher encountering "fluxus" in a modern context will almost certainly associate it with the avant-garde art movement; in legal sources it signals something categorically different — a boundary-making concept rooted in tidal geography and royal prerogative over navigable waters. The two meanings share only their Latin root and have no functional overlap.
Why It Matters in Research
Fluxus appears rarely in legal texts, and when it does, it marks a specific archaic practice: using the physical behavior of tidal waters to define legal boundaries. Researchers working in early English land law, foreshore disputes, or the historical boundaries of admiralty jurisdiction may encounter the phrase *per fluxum et refluxum maris* as a shorthand for the legal reach of the Crown's dominion over the sea and its margins.
Several research traps are worth noting. First, the term is nearly always encountered in Latin phrase form rather than standalone; a corpus search for "fluxus" alone will miss most relevant instances if phrase-level searching is not used. Second, the Dallison (*Dal. pl. 10*) citation referenced across all three source dictionaries points to a single locus of authority — researchers should be aware that the term's appearance in multiple dictionaries may represent serial copying from one source rather than independent corroboration of widespread usage. Third, the foreshore and tidal boundary questions to which fluxus relates connect to a larger body of doctrine on royal prerogative over the sea bed and littoral rights, making this term a gateway into that cluster rather than a freestanding concept. Fourth, modern researchers should exercise care not to conflate the archaic legal meaning with any reference to the 20th-century Fluxus art movement — a confusion that, while unlikely in most legal research contexts, could arise in interdisciplinary or historical scholarship.
Historical Dictionary Support
All three source dictionaries — Black's (1st ed.), Black's (2nd ed.), and Burrill's — are in near-complete agreement, each defining fluxus as "flow" and each anchoring the definition to the same illustrative phrase and the same Dallison citation. This uniformity is notable but should be read with caution: it suggests the dictionaries are drawing on a common source rather than independently surveying usage, which limits the evidentiary weight of their consensus.
Burrill's adds a small piece of useful contextual information by appending the entry for *flyma* (a fugitive or outlaw) immediately after fluxus in the same passage, reflecting the alphabetical proximity of the terms in the Saxon/Latin legal vocabulary of the period. This is a reminder that these terms exist within a dense lexical environment of old English legal Latin that rewards attention to surrounding entries.
None of the historical dictionaries elaborate on the substantive legal doctrine behind the phrase — they define the term linguistically but do not explain how tidal flow was used to demarcate jurisdiction or property. Researchers needing that doctrinal content must look beyond dictionary sources to treatises on English land law and maritime boundary doctrine.
Jurisdictional Note
Fluxus as a legal term is specific to old English law and has no recognized modern counterpart in U.S. or Commonwealth statutes. Its contemporary relevance, if any, arises in historical research into English foreshore and tidal boundary doctrine, which retains some influence in jurisdictions that inherited English common law rules governing littoral and riparian rights.