noun Etymology: probably alteration of monial ~ Date: 1567 a slender vertical member that forms a division between units of a window, door, or screen or is used decoratively, ~ transitive verb
MULLION
Meaning of MULLION in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012