n. 床柱

[ noun ]
any of 4 vertical supports at the corners of a bedstead
<noun.artifact>

Bedpost \Bed"post`\, n.
1. One of the four standards that support a bedstead or the
canopy over a bedstead.

2. Anciently, a post or pin on each side of the bed to keep
the clothes from falling off. See {Bedstaff}. --Brewer.