1. (n.) A slender bar or pier which forms the division between the lights of windows, screens, etc.

2. (n.) An upright member of a framing. See Stile.

3. (v. t.) To furnish with mullions; to divide by mullions.

Samson post baluster balustrade banister doorjamb doorpost gatepost hitching post jamb king post milepost post signpost snubbing post stanchion standard stile upright