ribbon worm vs nemertine

ribbon worm and nemertine both are nouns.

Word	Noun	Adjective	Verb	Adverb
ribbon worm	Yes	No	No	No
nemertine	Yes	No	No	No

As nouns, ribbon worm and nemertine are synonyms defined as:

ribbon worm and nemertine: soft unsegmented marine worms that have a threadlike proboscis and the ability to stretch and contract

Other synonyms of ribbon worm include nemertean, proboscis worm.

ribbon worm (noun)	nemertine (noun)
soft unsegmented marine worms that have a threadlike proboscis and the ability to stretch and contract	soft unsegmented marine worms that have a threadlike proboscis and the ability to stretch and contract