Mullion – A vertical bar between the panes of glass in a window

(Pronounced muh-lee-uhn)

To remember the definition of the word mullion, use the following mnemonic:

She became a multi-millionaire (mullion) selling the vertical bars between window panes.

Examples of mullion in a sentence

This mullion is made from aluminium.

The structure includes a mullion of over 2m tall.

The second storey window has a larger mullion than the ground floor.