mullion
UK[ˈmʌliən]US[ˈmʌliən]
n
a vertical bar between the panes of glass in a window or the panels of a screen.
Etymology
The word 'mullion' entered english in the 16th century, likely from the middle french 'moinel', meaning 'middle' or 'mullion'. This french term is thought to derive from 'moien', meaning 'middle', which itself comes from latin 'medianus'. The semantic link is clear: a mullion is the central, dividing element in a window frame. Over time, the spelling shifted to 'mullion' in english, solidifying its specific architectural meaning. The word's history illustrates how a general term for a central point evolved into a precise technical term for a structural component.
Analysis
the word is a simplex form. its origin is uncertain but likely related to middle french 'moinel' meaning 'middle'.
Examples
the large stained-glass window was divided by a slender stone mullion.
modern windows often use less obtrusive metal mullions between the glass panels.
the architect specified wooden mullions to match the traditional style of the house.