pillar vs caryatid

pillar and caryatid both are nouns.

Word	Noun	Adjective	Verb	Adverb
pillar	Yes	No	No	No
caryatid	Yes	No	No	No

As nouns, caryatid is a hyponym of pillar; that is, caryatid is a word with a more specific, narrower meaning than pillar:

pillar: (architecture) a tall vertical cylindrical structure standing upright and used to support a structure
caryatid: a supporting column carved in the shape of a person

Other hyponyms of pillar include atlas, telamon, newel, pilaster, pile, piling, spile, stilt, support column.

pillar (noun)	caryatid (noun)
(architecture) a tall vertical cylindrical structure standing upright and used to support a structure	a supporting column carved in the shape of a person
a vertical cylindrical structure standing alone and not supporting anything (such as a monument)
a fundamental principle or practice
a prominent supporter
anything that approximates the shape of a column or tower