Definition
An archaic Law French term meaning "to take away," "to take out," or "to remove." In historical legal usage, *oster* appears in procedural contexts to describe the removal of something from its place in a legal proceeding — most notably the removal of a document or pleading from the file of court records. The phrase *oste del file* (taken off the file) is the primary surviving example of the term in use, drawn from the Year Books of Henry VI's reign.
Common Language
Modern common usage (Wiktionary): A city in Chernihiv Raion, Chernihiv Oblast, Ukraine. No legal meaning in modern English.
Historical common usage (Webster's 1913): Not listed. The term had no common English currency by the nineteenth century.
The word *oster* belongs entirely to the Law French stratum of medieval English legal vocabulary. It has no modern English counterpart and carries no meaning outside historical legal sources. A researcher encountering this term is dealing exclusively with archaic procedural language from Year Book-era practice.
Common Confusion
*Oster* should not be confused with *ouster*, a substantively different legal term describing the wrongful dispossession of a person from property or office. The two words are related in Latin and Law French root (both derive from forms meaning "to remove"), but they diverged entirely in legal application. *Ouster* survived into modern law as a recognized doctrine; *oster* did not. A researcher scanning historical sources may encounter both spellings in close proximity and must distinguish them by context.
Why It Matters in Research
Researchers working in Year Book materials, early plea rolls, or treatises drawing on medieval English practice will encounter *oster* almost exclusively in its procedural sense — the removal of something from a court file. The phrase *oste del file* signals a discrete procedural act: a record or pleading was taken off the file, either by court order or clerical action. Understanding this prevents misreading what is a technical procedural notation as a substantive ruling.
Because *oster* appears only in Law French sources and vanished from active legal vocabulary well before Blackstone's era, it will not appear in nineteenth-century dictionaries or modern legal references except as an antiquarian entry. Burrill preserves it; most other sources do not. Researchers using Law Mind corpus materials that include Year Book transcriptions, Fitzherbert's *Natura Brevium*, or similar medieval sources should treat *oster* as a procedural term of art requiring the Law French interpretive lens, not the modern English one.
The Year Book citation in Burrill (H. 20 Hen. VI. 1 — Hilary Term, 20 Henry VI) places the term firmly in the 1440s. Any corpus document using *oster* or its inflected forms (*oste*, *ostee*) without explanation is almost certainly drawing on or transcribing material from that period or earlier.
Historical Dictionary Support
Burrill's Law Dictionary is the only shelf source for this term and provides the full extent of the surviving reference literature. Burrill's entry is sparse — a gloss and a single Year Book citation — which itself reflects how marginal this term was even by the mid-nineteenth century when Burrill compiled his dictionary. No other major historical legal dictionary (Bouvier, Black's early editions, Tomlin) appears to carry an independent entry for *oster* as a standalone term.
What Burrill does usefully preserve is the phrase *oste del file*, which anchors the term to a specific procedural context. Without that phrase, *oster* as a bare verb would be ambiguous across several possible procedural acts. The Year Book citation is genuine and traceable; researchers seeking the original context should consult Year Book reports for Hilary Term, 20 Henry VI.
Jurisdictional Note
*Oster* is a term of English legal history only. It has no American common law usage and no presence in civil law systems. Researchers working in colonial American records or early American court documents will not encounter it except in direct quotation from English sources.