Mullion

1. v. t. To furnish with mullions; to divide by mullions.
2. n. A slender bar or pier which forms the division between the lights of windows, screens, etc.
3. n. An upright member of a framing. See Stile.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.