annulus Meaning, Definition & Usage

noun a toroidal shape
ring; anchor ring; doughnut; halo.
- a ring of ships in the harbor
- a halo of smoke
noun (Fungi) a remnant of the partial veil that in mature mushrooms surrounds the stem like a collar
skirt.

plural Annuli

A ring; a ringlike part or space.
(Geom.) (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.
(Zoöl.) Ring-shaped structures or markings, found in, or upon, various animals.