centrepiece vs ornamentation

centrepiece and ornamentation both are nouns.

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

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

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

Other hypernyms of centrepiece include decoration, ornament.

centrepiece (noun)	ornamentation (noun)
something placed at the center of something else (as on a table)	the act of adding extraneous decorations to something
the central or most important feature	something used to beautify
	the state of being ornamented