mullion 
mullion definition
mul·lion (mul′yən)
noun
a slender, vertical dividing bar between the lights of windows, doors, etc.
Etymology: prob. altered < OFr moienel < moien, median < L medianus, middle: see mid
transitive verb
to furnish with or divide by mullions
Related Forms:
- mullioned mul′·lioned adjective
Browse dictionary definitions near mullion
Also Mentioned In