the central supporting pillar of a spiral or winding staircase 螺旋型楼梯中柱 ■(亦作 newel post)a post at the head or foot of a flight of stairs, supporting a handrail 楼梯端柱
语源
late Middle English: from Old French nouel 'knob', from medieval Latin nodellus, diminutive of Latin nodus 'knot'