Mullion
A mullion is a vertical element that forms a division between units of a window, door, or screen, or is used decoratively. When dividing adjacent window units, its primary purpose is to provide structural support to an arch or lintel above the window opening. Its secondary purpose may be as a rigid support to the glazing of the window. When used to support glazing, they are often teamed with horizontal elements called “transoms” which divide an opening’s upper part into one or more additional lights.
Transom (noun)
A crosspiece over a door; a lintel.
Transom (noun)
A horizontal dividing bar in a window.
Transom (noun)
A transom window.
Transom (noun)
Any of several transverse structural members in a ship, especially at the stern; a thwart.
Transom (noun)
The flat or nearly flat stern of a boat or ship.
Transom (noun)
The horizontal beam on a cross or gallows.
Transom (noun)
Items that have arrived over the transom.
“We are overwhelmed with transom resumes.”
“They only met the deadline by working most of the night and making a transom filing.”
Mullion (noun)
A vertical bar between the panes of glass or casements of a window or the panels of a screen.
Mullion (verb)
To shape into divisions by means of mullions.