monion
/ˈmʌnjən/(also monnion, munnion) rare. Now historical
noun
A piece of armour covering either the shoulder or the whole of the upper arm.
Origin
Mid 17th century; earliest use found in Robert Loveday (1620/21–1656), translator. From French †mougnon piece of armour that covers the shoulder, †moignon, apparently a specifically application of moignon, †mougnon stump of an amputated limb.