Definition
A unit of customary labor service in old English feudal law, consisting of a day's work performed by a ploughman. Avera was a form of villein service owed by tenants on the demesne lands of the crown — one of many specific obligations by which unfree tenants rendered agricultural labor in lieu of rent. The term appears primarily in Domesday Book and related medieval sources documenting the customary dues owed to the king within royal manors.
Common Language
Modern common usage (Wiktionary): Listed only as an alternative form of "averah," a Hebrew term for transgression. No independent common English meaning.
Historical common usage (Webster's 1913): Not present.
The modern Wiktionary reference to "averah" reflects an entirely unrelated word from a different language tradition. Researchers encountering "avera" in English legal or historical sources should not associate it with the Hebrew term; the two words share only superficial orthographic similarity and have no legal or conceptual connection.
Why It Matters in Research
Avera is a fossil term — it appears in medieval records and is carried into legal dictionaries primarily as a matter of historical completeness, not because it generates ongoing legal questions. Researchers are most likely to encounter it in two contexts: reading Domesday Book scholarship, where the term describes specific categories of tenant obligation recorded for royal manors; and tracing the broader vocabulary of villein tenure and customary service in secondary literature on English feudal land law.
The term belongs to a family of highly specific medieval labor obligations — alongside terms like boon-work, week-work, and carriagework — that were individually named and documented because customary services were hyperlocal and varied manor by manor. Avera specifically denoted ploughing service, distinguishing it from carting services or other agricultural work. When reading primary sources or antiquarian commentaries, precision matters: conflating avera with related terms like averium (draft animals or cattle) is an easy error that changes the meaning of a passage substantially.
Bouvier values avera at 8d., citing Jacob's Law Dictionary. That valuation reflects a commutation estimate — the monetary equivalent used when cash payment substituted for actual labor — and should be understood as a historical approximation rather than a fixed legal measure. Researchers should not treat it as authoritative outside its antiquarian context.
Historical Dictionary Support
Bouvier and Burrill agree on the core definition: a day's work of a ploughman, rendered as customary service on crown demesne lands. Burrill is more informative, grounding the term in Domesday Book and citing Spelman and Cowell as authority, which places avera within the well-documented tradition of medieval English tenure scholarship. Burrill also suggests a French derivation (ouvre, ouvrage — labor, work), though the word's precise etymological path through Law Latin is not fully settled across sources.
Both dictionaries treat the term as entirely historical even at the time of their composition. Neither suggests any continued application in contemporary law. What the historical dictionaries do not provide is context for how avera fit into the larger system of customary services — researchers needing that framework should consult Pollock and Maitland's History of English Law or secondary literature on villein tenure, as the dictionaries offer only the bare definition.