Material. The substance, or the matter from which an article is made; also the important thing, or element.
Mass. In physics it is that which in an article is always the same. It differs from weight in the particular that the mass of an article is the same, however far it may be from the center of the earth, whereas weight changes, and becomes less and less as it recedes from the center of the earth.
Margin. The edge; the principal differecee between this word and edge, is, that margin has reference also to a border, or narrow strip along the edge, as, for instance, the blank spaces at the edges of a printed page.
Medievral. Belonging to the Middle Ages.
Mercury. A silver-white liquid metal, usually called quicksilver, and rather heavy. It dissolves most metals, and this process is called amalgamation.
Militate. In determining a question, to have weight, or to influence a decision.
Mobility. Being freely movable; capable of quick change.
Modifieation. A change; making a difference.
Monitor. Advising or reproving. Advising or approving by way of caution.
Monstrosities. Anything which is huge, or distorted, or wrong in structure.