Newel

A novelty; a new thing.

The upright post about which the steps of a circular staircase wind; hence, in stairs having straight flights, the principal post at the foot of a staircase, or the secondary ones at the landings. See Hollow newel, under Hollow.

the central pillar of a circular staircase

the post at the top or bottom of a flight of stairs; it supports the handrail