Despite decades of scholarship on lexical borrowing in post-Conquest England, the vocabulary of the medieval countryside has remained largely outside the lens of contact linguistics - an oversight shaped by the long-standing assumption that French influence was confined to elite domains. At the same time, the multilingual reality of medieval England has made monolingual lexicography an increasingly inadequate tool: the Anglo-French, Medieval Latin, and Middle English lexicons of the period cannot be studied in isolation, yet no single trilingual resource has existed to study them together. This book provides that resource. Drawing on the historical dictionaries of all three languages and grounded in cognitive semantics, it constructs an onomasiological thesaurus of the vocabulary associated with the medieval English manor - concepts and referents attested from 1100 to 1500, arranged in conceptual groupings modelled on the structure of the \textit{Historical Thesaurus of English} and the \textit{Bilingual Thesaurus of Everyday Life in Medieval England}. The findings reframe received assumptions. Language contact shaped the rural lexicon far more deeply than the literature has claimed: French- and Latin-origin vocabulary dominates the terminology of manorial society, while native English holds its ground in the vocabulary of familiar locations. The asymmetry illuminates the social mechanics of borrowing in non-elite environments and carries implications for the history of English into the present day. This book will be essential reading for specialists in the history of the English language, the history of linguistics, historical lexicology and lexicography, and medieval studies, as well as for historical linguists and advanced students of language contact and multilingualism.