Definition
In old English law, marshy, moorish, or gravelly ground that is covered and overflowed by the sea or by great rivers. The term describes a specific category of land lying at the boundary between dry land and tidal or fluvial waters — ground that is periodically inundated by the ordinary flux of the sea rather than by exceptional flood or storm. Lord Hale applied the term specifically to the shore as covered by the ordinary tidal flow, a usage that tied the concept directly to questions of Crown ownership and the boundaries of the foreshore.
Common Confusion
Marettum should not be conflated with the foreshore in the modern sense, nor with mere marshland or wetland as understood in contemporary environmental or property law. The term is narrower and more technical than the general English word "marsh," and it carries specific implications about tidal influence and overflowing by the sea or great rivers — not standing water or inland bog. It also should not be confused with the related but distinct medieval categories of saltmarsh held by adjacent riparian owners versus foreshore vested in the Crown.
Why It Matters in Research
Marettum is a term of art in old English land law, appearing principally in disputes over the ownership and extent of Crown or manorial tidal lands. Its significance lies almost entirely in the foreshore and tidal boundary context: when researching historical questions about riparian rights, Crown grants of coastal or riverside lands, or the limits of manorial grants, a source using marettum is signaling that the disputed ground is neither clearly dry land nor open sea but occupies the legally contested intertidal zone.
Researchers using English Year Books, early Chancery records, or colonial land grants derived from English Crown practice may encounter the term in boundary descriptions. Because marettum directly implicates whether land falls within the jus publicum of the Crown or may be privately held, its appearance in a historical deed or grant is a reliable indicator that tidal ownership doctrine is in play. Co. Litt. 5a is the canonical reference point across all the source dictionaries, and Hale's De Jure Maris (pars 1, c. 6) is the primary jurisprudential authority extending the concept to the ordinary tidal shore. Researchers should consult Hale directly when the question involves the scope of the Crown's tidal rights, as that text provides the doctrinal framework that later English and American courts drew upon in foreshore cases.
The term is essentially obsolete in modern drafting and practice and will not appear in contemporary statutes or judicial opinions. Its research value is entirely historical.
Historical Dictionary Support
All three source dictionaries converge on the core definition — marshy ground overflowed by the sea or great rivers — and all cite Co. Litt. 5a as the primary authority. Burrill provides the most analytically complete entry, distinguishing two possible derivations (mare + tegere, or the French maret) and noting the dual usage: the stricter sense of moorish and gravelly ground covered at full sea, and Hale's broader application to the ordinary tidal shore. This distinction between the full-sea reading and the ordinary-flux reading is not trivial: the difference determines whether a given parcel lies within the intertidal zone subject to Crown rights or beyond it.
Rapalje and Lawrence add no independent analysis but notably append references to MARGIN and MARGIN OF THE STREAM — New York cases addressing adjacent concepts in a common-law riparian context. This adjacency is editorially suggestive: the historical compilers saw marettum as belonging to the same doctrinal neighborhood as stream-margin and boundary questions, even as they treated it as a purely English antique. Black's entry is the most compressed, essentially glossing the Burrill definition without the Hale nuance.
No source dictionary identifies any reported American case law applying the term marettum directly, which accurately reflects its disuse after the colonial period.
Jurisdictional Note
As a Latin term of old English law, marettum has no direct statutory life in any American jurisdiction. Where American courts addressed the underlying substance — Crown foreshore rights, tidal boundaries, and the extent of riparian grants — they drew on Hale's De Jure Maris and English common law principles without typically using the Latin term. Researchers in states whose land titles trace to colonial English grants (Massachusetts, Virginia, and others with early Crown patents) may find marettum in original grant language, but its interpretation in those jurisdictions will be governed by the common law of tidal boundaries as adopted and modified by each state's courts.