flower chain vs festoon

flower chain and festoon both are nouns.

Word	Noun	Adjective	Verb	Adverb
flower chain	Yes	No	No	No
festoon	Yes	No	Yes	No

As nouns, festoon is a hyponym of flower chain; that is, festoon is a word with a more specific, narrower meaning than flower chain:

Other hyponyms of flower chain include daisy chain, festoonery.

flower chain (noun)	festoon (noun)
flowers strung together in a chain	flower chains suspended in curves between points as a decoration
	an embellishment consisting of a decorative representation of a string of flowers suspended between two points; used on pottery or in architectural work
	a curtain of fabric draped and bound at intervals to form graceful curves

flower chain (verb)	festoon (verb)
	decorate with strings of flowers