Definition
Deunges (also deunx) is a term from Roman law denoting a fractional unit equal to eleven-twelfths (11/12) of the as, the standard Roman unit of measure used in law to express proportional shares of an inheritance, estate, or obligation. The as was divided into twelve equal parts called unciae (ounces); the deunges therefore represents eleven of those twelve parts, leaving one-twelfth remainder.
Why It Matters in Research
This term appears almost exclusively in historical sources dealing with Roman inheritance law and the law of fractions as applied to estates. Researchers encountering deunges in primary or secondary sources should understand it as part of a larger system of duodecimal fractions — the Roman as-system — used to express co-ownership shares, testamentary portions, and obligatory interests with mathematical precision.
The as-system generated a full vocabulary of fractional terms (uncia, sextans, quadrans, triens, semis, bes, dodrans, dextans, deunges, and so on) that appear throughout Roman juristic writing and resurface in early English common law commentary when writers sought to explain Roman inheritance rules. Blackstone references the system in his Commentaries precisely because English lawyers trained in the classical tradition needed to decode these fractions when reading Roman sources. A researcher working in probate history, civilian law, or comparative inheritance law may encounter the full ladder of as-fractions and should treat them as a coherent system rather than isolated terms.
Because the term has no operative role in modern Anglo-American law, it will not appear in contemporary statutes, cases, or regulations. Its research value is purely historical and comparative.
Historical Dictionary Support
Black's Law Dictionary (2nd Ed., Supplemental) defines deunges as "[i]n the Roman law. A division of the as, containing eleven unciae or duodecimal parts; the proportion of eleven-twelfths," citing 2 Blackstone's Commentaries 462, note. This is the standard account and reflects the orthodox civilian understanding.
The source base for this term is thin in English-language legal dictionaries — it is a specialist Roman law term that Black's preserves primarily as a reference aid for readers of Blackstone and civilian sources. Historical dictionaries agree on the arithmetic definition; there is no meaningful divergence. What the dictionaries do not explain is the practical context: in Roman succession law, heirs could take fractional shares of an estate expressed as portions of the as, and a testator could assign a deunges share to one heir while the remaining uncia went to another, allowing precise mathematical division of an estate without residue.
Jurisdictional Note
Deunges has no operative legal meaning in any modern common law or civil law jurisdiction. It is relevant only to Roman law scholarship, civilian legal history, and the interpretation of historical texts that employ the as-fraction system.