centrepiece vs ornament

centrepiece and ornament both are nouns.

Word	Noun	Adjective	Verb	Adverb
centrepiece	Yes	No	No	No
ornament	Yes	No	Yes	No

As nouns, ornament is a hypernym of centrepiece; that is, ornament is a word with a broader meaning than centrepiece:

centrepiece: something placed at the center of something else (as on a table)
ornament: something used to beautify

Other hypernyms of centrepiece include decoration, ornamentation.

centrepiece (noun)	ornament (noun)
something placed at the center of something else (as on a table)	something used to beautify
the central or most important feature

centrepiece (verb)	ornament (verb)
	make more attractive by adding ornament, colour, etc.
	be an ornament to