comatulid vs feather star

comatulid and feather star both are nouns.

Word	Noun	Adjective	Verb	Adverb
comatulid	Yes	No	No	No
feather star	Yes	No	No	No

As nouns, comatulid and feather star are synonyms defined as:

comatulid and feather star: free-swimming stalkless crinoid with ten feathery arms; found on muddy sea bottoms

comatulid (noun)	feather star (noun)
free-swimming stalkless crinoid with ten feathery arms; found on muddy sea bottoms	free-swimming stalkless crinoid with ten feathery arms; found on muddy sea bottoms