Dual Contract 
Illegal practice of having two contracts for the same transaction. For example, having one contract for a higher amount so that more money can be borrowed. 

Dual Divided Agency 
Representation of two or more parties in a transaction by the same real estate broker. 

Dual Listing 
Listing where a real estate broker represents both the buyer and seller, creating two principals. 

Duckbill Pliers 
Pliers with jaw ends that are tapered to a horizontal flat wedge. 

Duckboard 
Board that is placed over a muddy area to provide firm walking surface. 

Duct 
Thin sheet metal, shaped either round, square or rectangular, which is used to convey air at low pressure. 

Ducts 
Pipe that carries water, cooled air or wiring throughout a house. 

Ductile 
Workable. Material, as metal, able to be stretched or hammered thin without breaking, something not brittle, easily molded. 

Ductility 
The property of a material, often metal, which allows it to be formed and reformed, stretched or hammer, etc. 

Ductwork 
Network of ducts that has been installed, usually as part of an HVAC system. Ductwork is typically constructed from sheet metal. 

Ductwork, Preformed 
Ductwork which has been manufactured and shaped in a factory to use in special places where needed. 

Due-on-sale Clause 
Language in a mortgage stating that a loan must be fully repaid upon the sale of a home. 

Due Process 
The course of legal proceedings established by the legal system of a nation or state to protect individual rights and liberties. 

Dull 
1. Not brilliant. Dim. Not Shiny. 
2. Not pointed or sharp. Blunt. 

Dull Finish 
Non-glossy painted surface. 

Dull Rub 
Surface that has been rubbed to a dull sheen finish. 

Dummy 
Individual acting in the place of someone else in order to conceal his or her identity. 

Dumping 
Painting very quickly. 

Dumpy Level 
Level, which has a telescope and leveling vial, mounted on a rotating plate. Sight is taken through the telescope so that the point on the graduated rod that is level to the telescope can be found. The telescope is leveled using the leveling vial and then the crosshairs are lined up to a point on the rod. 

Dunnage 
Loose packing of any bulky material that is used around objects for shipping. 

Duplex 
Structure consisting of two separate family units, under the same roof. 

Duplex Nail 
A two headed nail on one shank, with one head about ½ inch higher, which is normally used for temporary installations, such as on concrete forms, since the nail can be easily removed with a claw hammer. Duplex nails are available in several sizes with the 16d, which is used for concrete forms, being the most commonly used. 

Duplex Receptacle 
Electrical outlet with space for two plugs. 

Duplicate 
To double. To copy. 

Duplicate Switching 
Wiring of multiple lighting fixtures in a way that half of the lamps can be worked independently of the other half, allowing for a lessening of the lighting level. 

Durability 
Ability to survive heavy wear and tear without deterioration. 

Durable Power of Attorney 
Legal instrument permitting one to grant others general or specific powers for administering their finances. 

Duralumin 
Trademark name of a strong aluminum alloy. 

Duress 
Act of forcing an individual or business to do something against their will and can be used as a legitimate defense in court to reverse the effect of the compelled act. 

Durham System 
Trade name of a rigid, threaded joint piping using recessed drainage fittings. 

Dust 
Powdery earth or other solid matter in pieces fine & small enough to be easily suspended in air. 

Dust Cover 
Covering, of any material, used to keep furniture or other items clean while not in use. Dust Free Area or surface that has no dust in the air or on any item. 

Dust Mask 
Mask, worn over nose and mouth when working, which filters out dust particles from the air. 

Dusting 
Powdery surface, which forms on newly, installed concrete. 

Dutch Arch 
Arch that is constructed from rectangular, rather than wedge shaped bricks, and is flat on the top area. 

Dutch Colonial Style 
Design that features a barn-like gambrel roof, overhanging eaves, a ground-level front porch and dormers. 

Dutch Door 
Horizontally divided door where the upper and lower halves open and close independently of each other. 

Dutch Hip Roof 
Roof with the upper gable ends of the roof being built with a short hip section. 

Dutchman Cut 
Method of cutting down a tree, which must fall in the opposite direction from its natural leaning tendency. To do this, an undercut is notched at 90 degrees to the direction of the fall and then the face cut made for the undercut is extended. A back cut is made on the side of the natural lean, a wedge is inserted and then the back cut is extended to fell the tree. 

Dwarf Partition 
Short wall or partition that does not go all the way to the ceiling. Also called a Dwarf Wall. 

Dwarf Wall 
Short wall or partition that does not go all the way to the ceiling. Also called a Dwarf Partition. 

Dwelling 
A place to live. A house. A residence. 

DWV Tubing 
Tubing, copper or plastic, which is used in the drain, waste, or vent parts of a plumbing system. 

DWV System 
Complete home waste removal system; drain, waste, vent. A drainage system depends on gravity to work rather than the water pressure needed in the water supply system. 

Dynamic 
Relating to energy or physical force in motion. Energetic. Vigorous. Forceful. 

Dynamic Braking 
Method of braking an electric motor, with the motor used as a generator and the electrical energy generated being dissipated in resistors. 

Dynamo 
Direct-current electric generator. A dynamoelectric machine. 

Dynamoelectric 
Having to do with the production of electrical energy from mechanical energy, or of mechanical energy from electrical energy. 

Dynamometer 
An apparatus for measuring force or power, for example, one for measuring mechanical power such as in an engine.