Definition
A Latin term from old English practice meaning "the octave" — that is, the eighth day after a feast day, counting the feast day itself as the first. In the medieval court system, the octaves were fixed return days on which parties were required to appear or on which procedural steps in litigation fell due. The octabis was thus a calendar term of art used to schedule and regulate proceedings in the common law courts, particularly in the period when the legal year was organized around the ecclesiastical calendar and its major feasts.
The term is a contracted or variant form of *octabis*, derived from the Latin *octo* (eight), and functions identically to the more commonly encountered term OCTAVE in the law dictionaries of the period.
Why It Matters in Research
This term will appear almost exclusively in medieval and early modern English legal records — plea rolls, court entries, and procedural texts such as Fleta — where proceedings were dated and scheduled by reference to feast-day octaves rather than by calendar date. A researcher encountering "octabis" in a source is dealing with a return day reference, not a substantive legal concept.
The practical trap: because the octave counts the feast day itself as day one, the "eighth day after" a feast in modern counting is actually the seventh day following. Misreading the interval can throw off date reconstruction in archival work.
The term largely disappears from legal usage after the medieval period. By the time legal dictionaries of the 18th and 19th centuries were compiled, octabis survived only as a historical curiosity requiring a cross-reference to "octave." Researchers working in post-17th-century sources are unlikely to encounter it in active procedural use.
Burrill cross-references the term directly to OCTAVE, which is the more fully developed entry and the more frequently appearing form in the sources. If you are tracing a specific return day — for example, "octabis Sancti Michaelis" (the octave of Michaelmas) — the entry under OCTAVE and the relevant feast day will provide the substantive context. The four principal terms of the English legal year (Hilary, Easter, Trinity, and Michaelmas) each carried associated return days including octaves, quindenes, and other intervals, and understanding how octabis fits into that system requires familiarity with the feast-day calendar as a whole.
Historical Dictionary Support
Burrill's Law Dictionary gives a minimal entry: "L. Lat. [from octo, eight.] In old practice. The octave. Fleta, lib. 2, c. 35. See Octave." This is the characteristic treatment for a term that functioned as a variant or abbreviation rather than as an independent concept. The citation to Fleta (a 13th-century Latin treatise on English law) places the term firmly in the medieval procedural tradition. No substantive definition is developed at the octabis entry because the term carries no independent meaning apart from its identity with octave.
The brevity of the entry reflects the approach common to 19th-century legal dictionaries when handling archaic Latin procedural terms: cross-reference to the primary form, cite the oldest authority, move on. Researchers should not read the thinness of the entry as evidence that the term was obscure — return days organized by feast-day octaves were the structural backbone of medieval court scheduling, and the concept itself was fundamental. The word octabis simply lost the competition with octave as the preferred form in later usage.
Jurisdictional Note
This term is specific to the medieval English common law tradition and its ecclesiastical calendar. It has no recognized counterpart in civil law systems or in post-medieval common law jurisdictions where the feast-day calendar ceased to govern court scheduling.