Русско-англо-русский юридический словарь

mainour (also manner). Law. A stolen object found in the possession of a thief when arrested. Chiefly in "taken (also found) with the mainour". (Oxford Living Dictionaries)

MAINOUR. In criminal law. An article stolen, when found in the hands of the thief. A thief caught with the stolen goods in his possession is said to be taken “with the mainour,” that is, with the property in manu, In his hands. 4 Bl. Comm. 307. The word seems to have corresponded with the Saxon “handhabend,” (q. v.) In modern law it has sometimes been written as an English word “manner,” and the expression “taken in the manner” occurs in the books. (TheLaw.com Law Dictionary)