chorionic villus vs villus

chorionic villus and villus both are nouns.

Word	Noun	Adjective	Verb	Adverb
chorionic villus	Yes	No	No	No
villus	Yes	No	No	No

As nouns, villus is a hypernym of chorionic villus; that is, villus is a word with a broader meaning than chorionic villus:

chorionic villus: one of the tiny villi that stick out of the fetal chorion and combine with the mother's uterine tissue to form the placenta
villus: a minute hairlike projection on mucous membrane

chorionic villus (noun)	villus (noun)
one of the tiny villi that stick out of the fetal chorion and combine with the mother's uterine tissue to form the placenta	a minute hairlike projection on mucous membrane