Dado Blade 
Adjustable saw blade in a radial arm or table saw used to cut the dado (or groove) in a piece of wood. The blade can be adjusted for the width of the dado to be cut either by stacking blades or dialing in eccentricity making the blade wobble back and forth as it rotates. 

Dado Joint 
Joint which is made by cutting a groove or dado into one piece of wood to allow another piece of wood to fit into it. This very strong joint is normally used in cabinet making. There is a straight dado joint which has a groove cut from edge to edge of the piece of wood. In the other type, the wood stops short of the edge so that the joint is not visible from the face of the piece. 

Dam 
A barrier that is built to hold back flowing liquid. 

Damage Deposit 
Prepayment required to cover damage, by a tenant, other than normal wear and tear. 

Damages 
1. Injury or harm to a person or entity. 
2. Money claimed by or ordered paid to someone as compensation for a loss or injury caused by another party. 

Damascening Metal
Use of an abrasive rod turned in a drill motor to make polished circles on a metal surface. 

Damp 
1. A slight wetness or moisture. 
2. A harmful gas sometimes found in mines. 
3. To slow the combustion of a fire by cutting off most of the air supply. 
4. To check or deaden the vibration of something. 
5. To reduce the fullness of waves. 

Damp Check 
Moisture-proof layer of material installed on the ground to prevent moisture penetration from the ground due to capillary action. Also called damp course. 

Damp Course 
Moisture-proof layer of material installed on the ground to prevent moisture penetration from the ground due to capillary action. Also called damp check. 

Damper 
The movable plate in a fireplace, which allows smoke to travel up the chimney's flue. 

Dampproofing 
1. Waterproofing treatment available as a coating or addition to concrete or mortar for use with masonry. 
2. To prevent moisture penetration by capillary action in masonry. 
3. To make moisture resistant. 

Danish Oil 
Used as a wood finish to preserve wood and to impart a sheen, this blend of drying oil and plastic in a vehicle such as mineral spirits is also sometimes used to stain wood. Also called Antique Oil. 

Darby 
Used to smooth and level wet concrete this straight wooden board is about four inches wide and three to eight feet long. 

Database 
Large collection of information in a computer, organized so that it can be updated, expanded and easily accessible for use. 

Datum Plane 
A real or assumed thing, used as a basis for calculations or measurements, as a level from which elevations and depths are measured in surveying. 

Datum Point 
Established reference point. 

Daub 
1. To cover or smear with sticky soft matter such as plaster. 
2. To paint coarsely or unskillfully. 
3. To cover a rough texture with adhesive material. 
4. A spot of adhesive. 

Days on the Market 
Period of time a property is listed for sale prior to being sold or removed. 

DBA (Doing Business As) 
Certification by a state that a principal is doing business under an assumed name. The Certification also contains the address where the business is being conducted. 

DC 
Direct current. Electric current that flows in one direction as opposed to alternating. Car batteries have direct current. 

Dead Air Space 
Space, isolated from circulation, which contains trapped air that creates thermal insulation 

Dead Blow Hammer 
Hammer that has a hollowed head that contains lead pellets which reduces the rebound when used. 

Dead Bolt 
A lock that requires a key to open from the outside and a turn bolt from the inside, which slides into a receptacle in the doorjamb. It is also called a deadbolt lock or a dead lock. 

Deadbolt Lock 
A lock that requires a key to open from the outside and a turn bolt from the inside, which slides into a receptacle in the doorjamb. It is also called a dead lock or a dead bolt. 

Dead End Street 
Street that terminates at one end has only one outlet and is not a through street. 

Dead Lock 
A lock that requires a key to open from the outside and a turn bolt from the inside, which slides into a receptacle in the doorjamb. It is also called a dead bolt or a deadbolt lock. 

Dead Storage 
Storage of inactive items, for a fee, for a certain period of time. 

Deaden 
1. To lessen the intensity or vigor of something. 
2. To treat with insulation to keep sound or vibration from going through. 
3. To take away the sensitivity of something. 

Dead End 
1. The end of a street that has no regular exit. 
2. An impasse. 
3. Capping off a piping system to terminate. 

Deadening Board 
Fiberboard that absorbs sound. 

Dead Flat 
Non-glossy painted area. 

Dead Load 
1. The burden a building structure creates on itself by virtue of its own weight as opposed to that caused by things that are not built into the building, which is called live load. Both the dead and live loads must be taken into consideration when designing a building. 
2. The fixed load that would be on the structure of a crane created by the rest of the crane attachment on the bridge. 

Dead Load Deflection 
Vertical deviations, which are caused by the weight and the weight of the attachments of the crane bridge. 

Deadline 
1. The latest time by which something must be completed or finished. 
2. Boundary that must not be crossed. 

Deadlock 
A lock that requires a key to open from the outside and a turn bolt from the inside, which slides into a receptacle in the doorjamb. It is also called a dead bolt or a deadbolt lock. 

Deadlock, Bored 
A lock with a key operated cylinder to open from the outside and an inside knob, with the cylinder fitting into a hole bored in the door. 

Deadlock, Mortise 
Dead bolt, which is installed into an opening, cut in the door. 

Deadman 
Buried mass of concrete or logs, which is used as an anchor for a cable or as a hidden support for a retaining wall.