Morion ~ A morion is a type of open helmet used from the middle 16th and
early 17th centuries, usually having a flat brim and a crest from front
to back. It was introduced in the middle of the 16th century,
contemporaneous with the exploration of north, central, and southern
America. Explorers like Hernando de Soto and Coronado may have used them for their foot soldiers in the 1540s.
Mantle ~ short lengths of cloth, usually in the livery colours, hung from the
torse on the helmet as an aid to identification. This is usually shown
as torn and ripped in battle when displayed in heraldry.
Misericorde ~ Mercygiver: A misericorde was a long, narrow knife, used in medieval times to deliver the death stroke (the mercy stroke, hence the name of the blade, derived from the Latin misericordia, "act of mercy") to a seriously wounded knight. The blade was thin enough so that it could strike through the gaps between armour plates. This weapon was used to dispatch knights who had received mortal wounds,
which were not always quickly fatal in the age of bladed combat; it
could also be used as a means of killing an active adversary, as during a
grappling struggle. The blade could be pushed through the visor or eye holes in the helm with the aim of piercing the brain, or thrust through holes or weak points in plate armor,
such as under the arm, with the aim of piercing the heart. The weapon
was known from the 12th century and has appeared in the armaments of Germany, Persia, and England.
Mangonel ~ a type of catapult or siege engine used in the medieval period to throw projectiles at a castle's walls. The exact meaning of the term is debatable, and several possibilities have been suggested. Mangonel may also be indirectly referring to the mangon, a French hard stone found in the south of France. It may have been a name for counterweight artillery (trebuchets), possibly either a men-assisted fixed-counterweight type, or one with a particular type of frame.