adornment vs decoration

adornment and decoration both are nouns.

Word	Noun	Adjective	Verb	Adverb
adornment	Yes	No	No	No
decoration	Yes	No	No	No

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

adornment: the action of decorating yourself with something colorful and interesting
decoration: the act of decorating something (in the hope of making it more attractive)

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

adornment: a decoration of color or interest that is added to relieve plainness
decoration: something used to beautify

Other hypernyms of adornment include ornament, ornamentation.

adornment (noun)	decoration (noun)
the action of decorating yourself with something colorful and interesting	the act of decorating something (in the hope of making it more attractive)
a decoration of color or interest that is added to relieve plainness	something used to beautify
	an award for winning a championship or commemorating some other event