hood ornament vs decoration

hood ornament and decoration both are nouns.

Word	Noun	Adjective	Verb	Adverb
hood ornament	Yes	No	No	No
decoration	Yes	No	No	No

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

hood ornament: an ornament on the front of the hood of a car emblematic of the manufacturer
decoration: something used to beautify

Other hypernyms of hood ornament include ornament, ornamentation.

hood ornament (noun)	decoration (noun)
an ornament on the front of the hood of a car emblematic of the manufacturer	the act of decorating something (in the hope of making it more attractive)
	something used to beautify
	an award for winning a championship or commemorating some other event