Active Door:
The leaf that opens first and the one to which the lock is (in a pair of doors) applied.

Adhesive:
A substance capable of holding material together by surface attachment; it is a general term and includes many adhesives inclusive of "glue".

Aluminum:
A light, bright metal used for window frames and window sash.

Architectural Millwork:
The ultimate in millwork detail and complexity - typically superior in design and detail to standard or stock millwork.

Astragal:
An astragal is a "T" shaped door component that is attached to a pair of doors to keep one door from swinging through the opening.

Ball Bearing Hinge:
A hinge equipped with ball bearings between the hinge knuckles to reduce friction. Mainly used for heavy doors for ease of opening.

Base Moulding:
A moulding applied where the floor and wall meet, forming a visual foundation. A base protects walls from kicks, bumps, furniture, and cleaning tools. A base may be referred to as one, two, or three member. The base shoe and base cap are used to conceal uneven floor and wall junctions. Also a relatively small moulding applied to the top of the base; when and with a two- member base it forms a three member base; also base cap.

Bead and Cove:
A sticking profile.

Bead:
A semicircular or rounded profile worked on wood; also a small moulding to secure glass or panels to doors, hence "glass bead".

Bevel:
To cut an angle other than a right angle, such as the edge of a bored or door.

Bottom Rail:
The bottom rail of a sash, door, blind or other panel assembly.

Brackets:
A wood member originally intended to support verge boards, hoods for porches or stoops, overhangs and cornices; today, primarily decorative.

Bypass Door Frame:
An interior door frame to accommodate two or more sliding doors that slide by or bypass each other in a horizontal direction sliding door frame.

Bypass Sliding Door:
One of two or more sliding doors that bypasses another door(s) in a door opening in a horizontal direction; a complete unit for such a door can be obtained consisting of two side jambs, header assembly with door track attached and necessary hardwood for hanging doors (doors may or may not be included); conserves space due to the exclusion of a required swing space.

Casing:
Casing is used to trim inside and outside door and window openings. Moulded or surfaced four sides pieces of various widths and thicknesses for trimming out door and window openings; casing may be classified as "exterior" or "interior", also classified as "side" or "head" casing.

Caulk:
To seal and make waterproof cracks and joints; e.g., joints around window and exterior door frames; also calk.

Caulking:
Compound for filling joints to prevent leakage of water and air. Weatherproof caulking is made of silicone base.

Code:
In the law, a collection of laws (regulations, ordinances, or statutory requirement) adopted by governmental (legislative) authority. Building Code: A code that is applicable to buildings, adopted and administered with the primary intent of protecting public health, safety and welfare. Model Code: A proposed code that is established within the procedural framework of a group of knowledgeable people, and is designed for adoption by governmental authority.

Condensation:
Atmospheric moisture that has condensed because it came in contact with a colder surface. The process of changing from a gaseous to a liquid or solid state.

Conduction:
The transfer of heat through matter, whether solid, liquid or gas

Contemporary:
A style of architecture using today's materials, planning and methods; attention tends to be directed toward present family tastes and needs and free from full reliance on the traditional; a style of architecture lying somewhere between "traditional" and "modern" and partaking somewhat of both.

Continuous Hinge:
A hinge designed to be the same length as the moving (also called Piano Hinge) part to which it is applied, for example, the lid covering the keyboard of a piano.

Coordinator:
A device used on a pair of doors to ensure that the inactive leaf is permitted to close before the active leaf. Necessary when an overlapping astragal is present and exit devices, automatic or self-latching bolts are used with closers on both door leaves.

Convection:
A transfer of heat through a liquid or gas when that medium hits against a solid surface. (Usage - "Forced convection" takes place outside when winds blow across a window pane; "natural convection" takes place inside when warmed or cooled air moves across the glass surface.

Cross-buck:
The panels of a door separated by intersecting diagonal rails and so arranged to simulate a sawhorse; especially one with the legs projecting above the cross bar; an arrangement of panels similar to the roman numeral "X"; also sawbuck.

Cross Rail:
The rail of a door.

Custom Millwork:
Millwork not manufactured in a standard size, patter or layout and which must be specially made in meeting a particular set of specifications; also architectural woodwork (millwork).

Cylinder:
The cylinder-shaped assembly (complete operating  unit) containing the tumbler mechanism and the keyway (plug, shell, tumblers, springs and actuating device)

Decay:
Disintegration of wood substance due to action of wood-destroying fungi; "advanced decay" or "incipient decay"; also rots, dotes, punk and doze.

Dentils:
A series of small square blocks uniformly spaced and projecting like teeth as used in cornice, front entrances and mantels; also a moulding.

Department of Housing and Urban Development, (HUD):
HUD's mission is to increase homeownership, support community development and increase access to affordable housing free from discrimination. To fulfill this mission, HUD will embrace high standards of ethics, management and accountability and forge new partnerships--particularly with faith-based and community organizations--that leverage resources and improve HUD's ability to be effective on the community level. For more information go to: http://www.hud.gov/

Divided Lights:
Window or door panes separated by bars and muntins.

Door Frames:
A group of wood parts machined and assembled to form an enclosure and support for a door; door frames are classified as exterior and interior door frames.

Door Handing:
A term to describe the direction a door swings -Example RH - right hand or RHR - right hand reverse.

Door Jamb:
The part of a door frame which surrounds and contacts the edges of the stiles and top rail of a door; jambs may be classified as (1) "head" or "side" jambs and (2) "plain" or "rabbeted".

Door Panel:
A sheet of thin lumber, plywood or composition material inserted into the frame formed by the stiles, rails and mullions of a door.

Door Skin:
The front or face panel (usually two or more plies) of a flush door.

Door Stop:
A device to stop the swing or movement of a door at a certain point.

Door Trim:
Trim for a door opening usually consisting of casing.

Double Action Door:
A door, usually interior, with special hinges or pivots which allow the door to function in both directions.

Dust-Proof Strike:
A strike with a spring plunger that completely fills the bolt hole when the bolt is not projected.

Dutch Doors:
A door usually exterior, with an upper and lower section that can be opened separately.