Mallet
Sort of large hammer in unforged metal, notably used by stonecutters.
Mandorla
Derived from the Italian word for “almond”, an oval-shaped glory of light enclosing the head of Christ or other sacred figure symbolizing their divine nature.
Mask
A replica or representation of the face.
Modillion
Also called a corbel in architecture, an ornamental cantilever on a façade. The corbel supports a weight, while the modillion plays a decorative role as well.