anchor ring vs annulus

anchor ring and annulus both are nouns.

Word	Noun	Adjective	Verb	Adverb
anchor ring	Yes	No	No	No
annulus	Yes	No	No	No

As nouns, anchor ring and annulus are synonyms defined as:

Other synonyms of anchor ring include doughnut, halo, ring.

anchor ring (noun)	annulus (noun)
a toroidal shape	(Fungi) a remnant of the partial veil that in mature mushrooms surrounds the stem like a collar
	a toroidal shape