Definition
Latin term for a seal, used in old English law to denote the physical impression made upon wax that authenticated a document or instrument. In its strictest historical sense, sigillum referred specifically to wax bearing an impressed mark — the wax alone, without an impression, did not constitute a seal. The term appears most often in legal Latin maxims and in older common law treatises discussing the formal requirements of deeds and other sealed instruments.
Common Language
Modern common usage (Wiktionary): A seal.
Historical common usage (Webster's 1913): A seal.
The ordinary meaning and the legal meaning align in the most basic sense — both point to a seal. The distinction worth noting is that the legal use of sigillum carried technical weight: at common law, the presence or absence of a seal (sigillum) determined whether an instrument was a deed and, in turn, whether consideration was required to enforce it. The word in legal contexts is not merely descriptive but marks a formal legal category.
Common Confusion
Sigillum is sometimes treated as synonymous with the modern English "seal" in all its current senses. That conflation can mislead researchers. Modern practice has largely abolished or diminished the legal significance of seals on contracts and instruments, but historical documents using sigillum invoke a specific formal requirement tied to wax impressions. A corporate seal, a notarial seal, or a stamped impression on paper called a "seal" today carries different legal weight — and in some jurisdictions, no weight at all — compared to what sigillum signified in the common law tradition.
Why It Matters in Research
Sigillum appears almost exclusively in Latin legal maxims and in pre-nineteenth-century English common law sources. Researchers working in the Law Mind corpus will encounter it primarily in treatise excerpts, glossaries, and discussions of sealed instruments (deeds, bonds, covenants) rather than in modern case law or statutes.
The most important research trap is temporal: documents and treatises through the early modern period use sigillum with the assumption that a wax impression is legally essential. Later American and English sources increasingly treat seals as formalities that can be satisfied by a printed scroll, the letters "L.S." (locus sigilli), or a gummed wafer — none of which fit the original meaning of sigillum. When reading historical sources, the presence of sigillum signals an older, stricter formal regime.
Researchers tracing the history of contract formalities, consideration doctrine, or the specialty/simple contract distinction will find sigillum appearing at pivotal points in the argument. Its decline as a term of art tracks the gradual erosion of the seal's legal significance across American jurisdictions throughout the nineteenth and twentieth centuries.
Cross-reference within the corpus: entries for SEAL, DEED, LOCUS SIGILLI, and SPECIALTY will extend the research thread begun here.
Historical Dictionary Support
The historical dictionary sources converge tightly on a single meaning with minimal variation. Black's first and second editions reproduce nearly identical text, both citing Coke's Institutes (3 Inst. 169) for the maxim: Sigillum est cera impressa, quia cera sine impressione non est sigillum — "A seal is a piece of wax impressed, because wax without an impression is not a seal." This maxim is genuinely instructive because it encodes the original formal requirement: the impression, not the wax alone, constitutes the sigillum. Burrill confirms the Latin derivation and situates the term in old English law before the entry cuts off. Anderson directs readers to SEAL without elaboration.
What the historical dictionaries do not address is the practical obsolescence of sigillum as a working legal concept. By the time Black's was first published, American courts had already largely moved away from requiring wax impressions, and the term was already receding into historical and scholarly usage. None of the source dictionaries flag this transition, which makes the WHY IT MATTERS note above especially important for corpus researchers who might take the dictionary entries as descriptive of current practice.
Jurisdictional Note
Seal requirements varied significantly across American jurisdictions and have been further modified or abolished by statute in most states. In jurisdictions that have formally abolished the seal's legal effect on contracts, sigillum retains only historical and antiquarian relevance. In a small number of states and in certain classes of instruments (real property conveyances, for example), formalities descended from the seal tradition persist in modified form.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Seals and Sealed Instruments; Formal Requirements of Deeds