M3U1L1L1I1O1N1E1D2
12 points
MULLIONED is validvalid
MULLION, to provide with vertical dividing strips [v]
MULLION, to provide the upright division between the panes of a window [v]
MULLION, to provide with vertical dividing strips [v]
MULLION, to provide the upright division between the panes of a window [v]