Annulus

[ænjulәs]

(noun.) (Fungi) a remnant of the partial veil that in mature mushrooms surrounds the stem like a collar.

Edited by Ethelred--From WordNet

(n.) A ring; a ringlike part or space.

(n.) A space contained between the circumferences of two circles, one within the other.

(n.) The solid formed by a circle revolving around a line which is the plane of the circle but does not cut it.

(n.) Ring-shaped structures or markings, found in, or upon, various animals.

Inputed by Edgar