Adiectio

Adiectio is a Latin noun meaning an addition, from the verb adicio “to add.” In classical Latin grammar, adiectio described the act or result of adding a word or phrase to a clause, often to enrich description or alter meaning; the added element may be a modifier, a clause, or sometimes an appositive.

Beyond grammar, the term is used in textual criticism and manuscript studies to refer to a later addition to a text—such as marginal glosses or a clause inserted by a scribe or editor. It is distinct from interpolation (insertion by a later redactor) and from emendation (correction of the text). In this sense adiectio covers both small editorial additions and larger insertions that affect the texture of a passage.

In legal and documentary Latin, adiectio denotes an appended provision, grant, or statement added to a charter or decree after its original composition. Such adiectio could be invoked to record new obligations, privileges, or donations.

Today the term is largely historical and appears in studies of Latin grammar, rhetoric, manuscript culture, and paleography. It illustrates how ancient and medieval authors, editors, and scribes manipulated texts by adding material to enhance or adapt them.