Definition
A Latin term from the civil law meaning to undersign or subscribe — that is, to sign or seal beneath a document as a mark of authentication or assent. The term derives from sub (under) and signare (to seal or sign), and in its strictest etymological sense means to seal underneath. In practice within Roman law, subsignare was used more broadly to denote the act of writing one's name below a text — what would today be recognized as subscribing or signing a document.
The act accomplished by subsignare corresponds to what modern law calls a subscription: the placement of a signature at the foot or close of a written instrument to authenticate it, bind the signer, or attest its contents.
Common Language
Modern common usage (Wiktionary): Wiktionary does not carry an entry for subsignare, reflecting its status as a term confined to Latin legal and scholarly texts with no living common usage.
Historical common usage (Webster's 1913): Webster's 1913 does not include subsignare. The related English verb "subscribe," however, appears as meaning "to write underneath" or "to sign at the bottom of a document."
The gap here is not between common and legal meaning but between Latin source and English derivative. Subsignare is the Latin root from which the English legal term "subscribe" (and its noun form "subscription") directly descends. Understanding subsignare clarifies why subscription in legal instruments means signing at the foot of a document, not merely agreeing to receive something.
Common Confusion
Subsignare is sometimes loosely equated with signare (simply to seal or sign) or with signare in dorso (to endorse, i.e., to sign on the back). The distinction matters in historical document analysis: subsignare and its noun subsignatio refer specifically to signing or writing below the body of a text — the physical position of the authenticating mark. An endorsement or dorsal notation is a different act, placing the mark on the reverse rather than the underside or foot of the instrument.
Why It Matters in Research
Researchers working with civil law texts, canon law manuscripts, or early modern legal instruments will encounter subsignare and its noun form subsignatio in contexts involving documentary authentication. Several research traps deserve attention.
First, the meaning shifted even within Roman usage. As Burrill records from the Digests, the ancient Romans used subsignatio in the sense of adscriptio — a written addition or annotation — not merely a formal signature or seal. A researcher who reads subsignare in a classical Roman source and assumes it means a modern-style subscription may misread what was actually an authenticating notation or marginal addition.
Second, subsignatum (the past participle) appears in source texts as the descriptor for a document that has been subscribed or authenticated. Identifying whether a document is described as subsignatum versus simply signatum may indicate differences in the formality or authentication of the instrument.
Third, because the term spans civil law, canon law, and early modern notarial practice, its precise force depends on the legal system and period in question. In notarial contexts, subsignare often appeared as part of the notarial completion formula, distinct from the witness signatures or the principal party's execution.
Finally, researchers should not allow the term's apparent simplicity — it looks like it just means "sign underneath" — to obscure the doctrinal weight it carries in contexts where subscription was a formal legal requirement for validity. The distinction between an instrument that was sealed (signatum) and one that was subscribed (subsignatum) could determine enforceability in the source legal system.
Historical Dictionary Support
Burrill's Law Dictionary is the primary English-language legal dictionary source for this term, and its entry is characteristically careful. Burrill correctly identifies both the strict etymological sense (to seal under) and the broader usage attested in the Digests, quoting the passage that subsignatum dicitur quod ab aliquo subscriptum est — that is said to be subsigned which has been subscribed by someone — and noting that the ancient Romans used subsignatio in place of adscriptio, meaning a written addition.
This is a meaningful distinction that Burrill surfaces well: the term did not simply mean "to put one's seal below" in archaic Roman usage, but was functionally equivalent to writing something in addition to, or alongside, the main text. This usage is older than the more formalized subscription sense that appears in later civil law and notarial practice.
Burrill's entry is necessarily brief, and the corpus of historical legal dictionaries in English does not develop the term further. Researchers seeking fuller treatment should consult Latin civil law glossaries and Digest commentaries directly, particularly those addressing the requirements for documentary authentication under Roman law.
Jurisdictional Note
Subsignare belongs to the civil law tradition and does not appear as operative terminology in common law jurisdictions. It surfaces in historical research on Roman law, canon law, and the mixed civil-common law systems of Scotland, Louisiana, Quebec, and South Africa, as well as in ecclesiastical document analysis. It carries no direct operative force in modern U.S. or English law, though its English derivative "subscribe" retains legal significance in instrument execution requirements across many jurisdictions.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia — Roman Law (for civil law documentary practice and authentication requirements); Subscription and Authentication of Documents (for the historical and doctrinal development of signing requirements in legal instruments).