mul·​lion | \ ˈməl-yən How to pronounce mullion (audio) \

Definition of mullion

: a slender vertical member that forms a division between units of a window, door, or screen or is used decoratively

Keep scrolling for more

Other Words from mullion

mullion transitive verb

Examples of mullion in a Sentence

Recent Examples on the Web

Black window mullions and door and chair frames add graphic punch in a family vacation home on Sullivan's Island, South Carolina. Sarah Yang, House Beautiful, "Top Pin of the Day: A Beachy Dining Room," 2 June 2014 There are a variety of code violations with the most costly being a mullion that needs to be replaced on a door. Evan Frank, Milwaukee Journal Sentinel, "No liquor license for Olympia Resort until new owners make repairs, officials say," 25 June 2018 Also think about making a statement with glass cabinet doors – traditional styles usually feature mullions, while contemporary do not. Michelle Martin For Toll Brothers, Detroit Free Press, "Top 6 trends in the kitchen and bath," 16 May 2018 The kitchen opens to a large breakfast room where glasses and dishes are displayed in a built-in hutch with glass mullion doors. Karen A. Avitabile,, "Property of the Week: 56 Old Stone Crossing, West Hartford," 3 Aug. 2017 The Monroe house is painted in a warm terracotta color, with olive trim and front-step metal railings (added by the current owners) that echo the angular window mullions. Steve Bennett, San Antonio Express-News, "2 Beacon Hills homes came from 1904 St. Louis World’s Fair," 29 Mar. 2018 Everything about the house is intended to draw the visitor's eye to the outdoors, from the seven terraces to mitered glass windows that eliminate visually jarring mullions. Cindy Decker,, "Falling for Frank Lloyd Wright in Pennsylvania's Laurel Highlands," 4 May 2017 Now a fully functioning home, with just one bedroom, the Lodge also features a bathroom, living room, decorative spiral staircase and dining room complete with mullion windows and cast iron Victorian fireplace. Emma-louise Pritchard, House Beautiful, "The Smallest Castle in the UK Is Up for Sale," 3 Apr. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mullion.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of mullion

1567, in the meaning defined above

History and Etymology for mullion

probably alteration of monial mullion

Keep scrolling for more

Learn More about mullion

Dictionary Entries near mullion








Statistics for mullion

Look-up Popularity

Time Traveler for mullion

The first known use of mullion was in 1567

See more words from the same year

Keep scrolling for more

More Definitions for mullion



English Language Learners Definition of mullion

: an upright piece of wood, stone, metal, etc., that separates two windows

More from Merriam-Webster on mullion

Rhyming Dictionary: Words that rhyme with mullion Encyclopedia article about mullion

Comments on mullion

What made you want to look up mullion? Please tell us where you read or heard it (including the quote, if possible).


appealing forcibly to the mind or reason

Get Word of the Day daily email!

Test Your Vocabulary

Farm Idioms Quiz

  • cow coming home
  • What does 'poke' refer to in the expression 'pig in a poke'?
True or False

Test your knowledge - and maybe learn something along the way.


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!