Webster's 1828 Dictionary
MAINOR
n.[L. a manu, from the hand, or in the work. ] The old law phrase, to be taken as a thief with the mainor, signifies, to be taken in the very act of killing venison or stealing wood, or in preparing so to do; or it denotes the being taken with the thing stolen upon him.
Webster's 1913 Dictionary
MAINOR
Main "or, n. Etym: [Anglo-Norm. meinoure, OF. manuevre. See Maneuver. ](O. Eng. Law )
Defn: A thing stolen found on the person of the thief.
Note: A thief was said to be "taken with the mainor, " when he was taken with the thing stolen upon him, that is, in his hands. Wharton. Bouvier.