masonry bit: A drill bit that is used for drilling through masonry.

mastic: Mastic is a type of adhesive used to bond items where waterproofing is important.

meeting rails: The top rail of the bottom sash and the bottom rail of the upper sash meet and are slanted and weather-stripped to form a tight seal between the rails.

metal glazing points: Triangular metal glazing points the small pieces used to hold a glass pane in position until you apply the glazing putty.

microwave sensors: A sensor that uses microwaves to detect motion.

mildewcide: A chemical that will actually kill the fungus that causes mildew.

mineral spirits: A solvent made from petroleum and used primarily as paint thinner.

mineral wool insulation: Mineral wool insulation, or rock wool insulation, is similar to fiberglass. It is more expensive and somewhat more difficult to find, but doesn’t cause the same itchy reaction. It looks like dryer lint and can be dusty when handled. Rock wool comes in loose fill that can be blown in poured out of bags."

molding: The term molding refers to larger and typically more ornamental finish strips.

molly bolt: A piece of hardware used to anchor drapery rods into hollow walls. The molly bolt includes an anchor plug and a screw with sides that spread out behind the wall to hold it in place.

mortar: Mortar is the bonding mixture that is used to cement bricks and stones together.

mortise: A mortise is a shallow recess in a wood frame to seat a piece of hardware flush with the wood.

mounting strap: The metal brace that lays across a ceiling box and to which you mount a fixture base.

multiple drop match: A multiple drop match is the most complex pattern match. It can take four or more strips to repeat the vertical design. A good example of this is a dense paisley pattern.