A vertical bar or divider in the frame between windows, doors and other openings that supports and holds items such as panels, glass, sashes, and sections of a curtain wall.

"vertical column between the lights of a window," 1560s, metathesis of Middle English moyniel (early 14c.), from Anglo-French moinel, noun use of moienel (adj.) "middle," from Old [..]

The vertical member of a sash, window or door frame between openings in a multiple opening frame. SPACE MULL: Two or more units mulled together with a space left between the units. The jamb extension [..]

A vertical bar or divider in the frame between win dows, doors, or other openings.

A horizontal or vertical member that supports and holds such items as panels, glass, sash, or sections of a curtain wall.

Vertical division member between windows or doors

A component used to structurally join two window or door units.

A combined guide assembly joining two adjacent rolling doors where center guide is hinged and motorized to lift up and out of the way to expose a full opening width when both doors are open.

A combined guide assembly joining two adjacent rolling doors, grilles or counter doors where center guide is removable to expose a full opening width.

A horizontal or vertical member that supports and holds such items as panels, glass, sash, or sections of a curtain wall.

A slender vertical bar between panes or section of windows, screens, etc.

The upright or vertical member dividing the panels in a door  A mullion is also the vertical member of a sash, window or door frame between openings in a multiple opening frame  The mullion is known a [..]

Vertical bar dividing the lights of a window.    (Wood, Margaret. The English Medieval House, 413)

(n) a nonstructural vertical strip between the casements or panes of a window (or the panels of a screen)

A vertical divider in the frame between windows, doors, or other openings.

Slender framing which divides the lights or panes of windows.

A vertical bar or divider in the frame between windows, doors, or other openings.

The upright or vertical member dividing the panels in a door. A mullion is also the vertical member of a sash, window or door frame between openings in a multiple opening frame. The mullion is known as the "mullion center". Frames are termed "mullions", ""triples", or "quadruples", depending on whether t [..]

A vertical member (usually wood or metal) to structurally join two window or door units.

A major structural vertical or horizontal piece that combines two or more windows together.

A component used to structurally join two window or door units. Multipoint lock:

an upright support separating the main panels of a large window.

The vertical bar dividing the lights in a window.

A mullion is the vertical structural element which divides adjacent window units.

Window divided into two vertical parts by a small column or pilaster. Frequently found in Romanesque, Gothic and Renaissance buildings.

Upright member dividing window panels on a building.

An extrusion that joins windows. A sealant is applied between the units to prevent air and water leakage. A bullnose or profiled moulding is used on the inside and outside to cover this joint.

A vertical bar between the panes of glass or casements of a window or the panels of a screen.