1. [n]  the central pillar of a circular staircase
2. [n]  the post at the top or bottom of a flight of stairs; it supports the handrail

NEWEL is a 5 letter word that starts with N.

1. \New"el\, n. [From {New}. Cf. {Novel}.]
   A novelty; a new thing. [Obs.] --Spenser.
   
   

2. \New"el\, n. [OF. nual, F. noyau sone, of fruit, noyau
   d'escaler newel, fr. L. nucalis like a nut, fr. nux, nucis,
   nut. Cf {Nowel} the inner wall of a mold, {Nucleus}..]
   (Arch.)
   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}.