Demain

Demaine, Demayne, Demaygne, Demeyne, Bemeigne, Demesne, L. Fr. <fe Eng. [L. Lat. demanium, domanium, dominicum,'] In old English law. A term used to denote a lord's chief manor place, with the lands thereto belonging, which he and his ancestors had, from time out of mind, kept in their own hands or manual occupation. Termes de la ley, Blount, Derived, accordingly, by Lord Coke, from the Fr. de, of, and main, hand, i. e. manured [mainoured] or received by the hand. Hence manual occupation, possession or receipt.

Co, Litt. 17 a.

This derivation, however, is not approved by Spelman, who rejects also the word demesne and its etymology, and considers demain as derived from the Lat. dominicum, Spelman, voc: Dominicum, See Demesne, Dominicum.