Definition
In old European law, an incident or ancillary thing — that which is attached to or follows upon something else as a dependent or subordinate element. The term appears in medieval Latin legal usage to describe a matter or legal relation that inheres in, or accompanies, a principal subject. Where the principal subject is extinguished, the adjunctum falls with it (see the maxim extincto subjecto, tollitur adjunctum — when the subject is extinguished, the incident is also extinguished).
Burrill also records a secondary, procedural usage in which the related verb form (adjungere or its cognates) meant to cite or summon to court, to sue, or to attach — functions associated with bringing a party or their property within the jurisdiction of an early Germanic or Frankish tribunal.
Why It Matters in Research
This term is encountered almost exclusively in sources dealing with early medieval European law — Salic law, Frankish formularies, and the glossarial literature that grew up around them. Researchers working in that stratum of legal history will meet adjunctum primarily in two distinct but easily confused contexts:
First, as a substantive concept: adjunctum in this sense is the civilian and canon law idea of an incident or appurtenance — the thing that rides along with the principal. This usage connects directly to the Latin maxim literature and to treatises on property, obligations, and tenure, where the extinction of a principal right or subject carries away all its incidents. Researchers tracing how medieval property concepts migrated into English law should look for this usage in glossators and in early English equity sources that drew on civil law reasoning.
Second, as a procedural verb-concept: Burrill's entry collapses the noun adjunctum with what appears to be a related verb usage drawn from the Lex Salica and Marculfi Formulae, describing the act of summoning or attaching. These are distinct functions, and conflating the substantive and procedural senses will mislead a researcher. The procedural sense corresponds closely to what later English law would call attachment or citation, and Burrill himself cross-references attachiare as the equivalent term in that tradition.
Researchers should be alert to the fact that this term has very thin coverage in English-language legal dictionaries. Burrill is one of the few common reference works to record it at all, and his entry is compressed to the point of ambiguity. Latin civilian dictionaries, Du Cange's Glossarium Mediae et Infimae Latinitatis, and Spelman's Glossarium Archaiologicum (which Burrill cites) will provide fuller context for either sense.
Historical Dictionary Support
Burrill's Law Dictionary is the primary English-language legal dictionary source for this term. Burrill's entry is notable for its brevity and its dual function: it defines adjunctum as "incident" and simultaneously points to a procedural usage (to cite, summon, sue, or attach) drawn from the Lex Salica (tit. 59) and Marculfi Formulae (lib. 1, c. 21), with a cross-reference to Spelman. The entry does not attempt to reconcile the substantive and procedural senses, leaving that work to the reader.
The Spelman cross-reference is instructive. Spelman's Glossarium Archaiologicum, a genuine and well-regarded source on medieval legal terminology, treated adjungere and related forms in the context of Frankish legal procedure. Burrill's equation of this usage with attachiare reflects a recognized scholarly tradition of reading early Germanic summoning and distraint practices as forerunners of English attachment.
No equivalent entry appears in Tomlin's Law Dictionary, Jacob's Law Dictionary, or Black's Law Dictionary in its standard editions, indicating that adjunctum was regarded as too archaic or too narrowly civilian for inclusion in dictionaries oriented toward English common law practice.
Jurisdictional Note
Adjunctum belongs to the law of early medieval continental Europe, primarily Frankish and Germanic systems. It has no operative role in modern common law or civilian jurisdictions as a term of art. Its relevance is historical and comparative.