Metacarpal, the part of the hand between the wrist and the fingers.
Metallurgy, the art of working metals.
Metatarsal, the middle part of the foot.
Miocene, the middle or second epoch of the Tertiary.
Molar, a grinding tooth.
Mold, or mould, a prepared cavity used in casting; to form or shape; fine soft earth.
Mollusca, an order of invertebrate animals having a soft, fleshy body, which is inarticulate, and not radiate internally.
Moraine, a line of blocks and gravel extending along the sides of separate glaciers, and along the middle part of glaciers formed by the union of one or more separate ones.
Nebulous, having a faint, misty appearance; applied to uncondensed gaseous matter.
Neolithic, new stone age; a term applied to the more modern age of stone.