Definition of mullion
: a slender vertical member that forms a division between units of a window, door, or screen or is used decoratively
Recent Examples of mullion from the Web
The mullion wall method was revived in the 1950s, and Minoru Yamasaki used this same idea in his 1966 design for the World Trade Center in lower Manhattan.
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.
Origin and Etymology of mullion
probably alteration of monial mullion
First Known Use: 1567
MULLION Defined for English Language Learners
Definition of mullion for English Language Learners
: an upright piece of wood, stone, metal, etc., that separates two windows
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