Definition
A Latin term from old procedural practice meaning "to answer" or "about to answer." Used in early common law writs and pleading documents to describe a defendant's required appearance or obligation to respond to a legal proceeding. Functionally equivalent to the phrase *ad respondendum*, with which it is interchangeable in historical sources.
Why It Matters in Research
This term appears almost exclusively in medieval and early modern English legal records, Latin writs, and treatises rooted in the pre-modern common law. Researchers encountering *responsurus* in historical documents should treat it as a procedural marker signaling an obligation to appear and answer — the same function served by *ad respondendum* — rather than as a term carrying any distinct substantive meaning.
The principal research trap is treating *responsurus* and *ad respondendum* as technically differentiated terms when historical sources, including Burrill, treat them as synonyms. A researcher finding one form in a writ or pleading record should search for the other when tracing procedural lineage across sources.
Because the term appears in Fleta (a late thirteenth-century treatise on English law), researchers working with early Year Books, plea rolls, or Latin writs from the reign of Edward I onward may encounter it in its original procedural context. It will not appear in modern practice materials. Its presence in a document is a reliable indicator that the source predates or consciously imitates medieval Latin pleading form.
Cross-references to *capias ad respondendum* — the writ commanding arrest of a defendant to compel an answer — are the most productive next step for researchers following this term through the corpus.
Historical Dictionary Support
Burrill's Law Dictionary provides the only substantive treatment in the Law Mind shelf, and it is brief: *responsurus* means "to answer" in old practice, with citation to Fleta, lib. 2, c. 65, § 11, and a direct equivalence to *ad respondendum*. No elaboration is offered beyond this cross-reference, and no other historical dictionary in the Law Mind corpus appears to have given the term a standalone entry. This is consistent with *responsurus* being a grammatical form (future active participle of *respondere*) that appears inside Latin writs rather than as a legal term of art with its own doctrinal content.
The citation to Fleta is noteworthy. Fleta is a late thirteenth-century English legal treatise, likely composed around 1290, written in Latin and closely modeled on Bracton. Its appearance here anchors *responsurus* firmly in the earliest stratum of English common law procedural writing. Researchers should note that Burrill does not quote the Fleta passage or explain the procedural context further, so the entry functions as a pointer rather than an explanation.