Editing Mullion (section)

{{short description|Architectural element}}
{{other uses}}
[[File:Open-sky-bifora-SanFrancesco-Lodi.JPG|thumb|right|A mullioned window in the church of [[San Francesco (Lodi)|San Francesco]] of [[Lodi, Lombardy]]]]

A '''mullion''' is a vertical [[structural element|element]] that forms a division between units of a window or screen, or is used decoratively.<ref>{{Cite web|url=http://www.merriam-webster.com/dictionary/mullion|title=Definition of MULLION|website=www.merriam-webster.com|language=en|access-date=2017-09-20}}</ref> It is also often used as a division between double doors. When dividing adjacent [[window]] units its primary purpose is a rigid support to the glazing of the window. Its secondary purpose is to provide structural support to an arch or [[lintel]] above the window opening.  Horizontal elements separating the head of a door from a window above are called [[Transom (architectural)|transom]]s.