Definition
A Latin term from old English law meaning a following up or pursuit. The word denotes the active act of pursuing a legal claim, remedy, or proceeding — tracking the procedural idea that a party must actively carry forward their cause rather than let it rest. In its historical usage, *prosecutio* captured the essential requirement that a litigant press on with their suit, following it through the courts to conclusion.
The term belongs to the Latin vocabulary of medieval English legal practice and does not function as a distinct legal doctrine in modern law. Its significance is primarily as a root concept and terminological ancestor underlying the modern word "prosecution" and related procedural principles.
Common Language
Modern common usage (Wiktionary): Not listed as a contemporary English term. The term exists only in Latin and in historical legal contexts.
Historical common usage (Webster's 1913): Not separately defined; treated as the Latin root from which "prosecution" and "prosecutor" derive.
Editorial note: Because *prosecutio* has no meaningful modern common usage independent of its legal-historical context, the gap between common and legal meaning is not a productive distinction here. The term is best understood as a technical term of art from medieval Latin legal practice, not a word a non-specialist would encounter in ordinary language.
Why It Matters in Research
Researchers working in early English legal records — particularly those involving writs, pleading forms, or procedural manuals from the medieval and early modern periods — will encounter *prosecutio* as a term describing what a party was required to do to keep a suit alive. The concept of following up was procedurally significant: failure to prosecute (*non prosecutio* or *non prosequitur*) could result in dismissal or judgment against the party who abandoned pursuit of their claim.
Understanding *prosecutio* is also essential for tracing the genealogy of modern prosecutorial concepts. The modern criminal "prosecution" inherits its core meaning directly from this Latin term, but the shift from a general procedural idea (any party following up any claim) to a narrower criminal-law meaning (the state pursuing a criminal defendant) is a significant conceptual evolution that researchers should not elide. Historical sources using *prosecutio* may be describing civil pursuit of a remedy, not anything resembling modern criminal prosecution.
Fleta, the 13th-century legal treatise cited by Burrill, is a significant primary source for this term and for medieval English procedural law generally. Researchers consulting Burrill's citation to Fleta, lib. 3, c. 2, § 2 should be aware that Fleta is itself a derivative work drawing heavily on Bracton, and both texts use Latin procedural vocabulary that can be misleading if read through a modern lens.
Historical Dictionary Support
Burrill's Law Dictionary provides the sole historical dictionary entry for this term in the Law Mind corpus. The entry is minimal — a two-word gloss ("a following up; pursuit") with a single citation to Fleta — but it accurately captures the functional meaning of the term in its medieval context.
The brevity of the Burrill entry reflects the term's status as foundational vocabulary rather than a term requiring elaborate definition. It is the kind of word that appears in treatises and year books as part of the expected Latin procedural vocabulary, not as a term in need of disambiguation. Historical dictionaries more generally do not spend significant effort on *prosecutio* because by the time English legal dictionaries were being compiled in earnest (17th century onward), the Latinized form had largely given way to the anglicized "prosecution."
What Burrill's entry does not address — and what researchers should keep in mind — is the transition from *prosecutio* as a general procedural concept applicable to any party in any proceeding to "prosecution" as a term primarily associated with criminal proceedings brought by state authority. That evolution is not visible from the dictionary entry alone and requires attention to the broader arc of English legal history.