newel vs newel post

newel and newel post both are nouns.

Word	Noun	Adjective	Verb	Adverb
newel	Yes	No	No	No
newel post	Yes	No	No	No

As nouns, newel and newel post are synonyms defined as:

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

newel (noun)	newel post (noun)
the central pillar of a circular staircase	the post at the top or bottom of a flight of stairs; it supports the handrail
the post at the top or bottom of a flight of stairs; it supports the handrail