Definition of mainour in English:

mainour

(also manner)

noun

historical
  • Law. A stolen object found in the possession of a thief when arrested. Chiefly in "taken (also found) with the mainour".

Origin

Late Middle English; earliest use found in Domesday Ipswich. From Anglo-Norman meinoure, meinovre, main overe handiwork, theft, stolen goods from post-classical Latin manopera.