[syn: annulus, skirt]
The Collaborative International Dictionary of English v.0.48:
Annulus \An"nu*lus\, n.; pl. Annuli. [L.]
1. A ring; a ringlike part or space.
(a) A space contained between the circumferences of two
circles, one within the other.
(b) The solid formed by a circle revolving around a line
which is the plane of the circle but does not cut it.
3. (Zool.) Ring-shaped structures or markings, found in, or
upon, various animals.
WordNet (r) 3.0 (2006):
n 1: a toroidal shape; "a ring of ships in the harbor"; "a halo
of smoke" [syn: ring, halo, annulus, doughnut,
2: (Fungi) a remnant of the partial veil that in mature
mushrooms surrounds the stem like a collar [syn: annulus,