annulus

rengas A ring- or donut-shaped area or structure.
puhekieltä The region in a plane between two concentric circles of different radius.
puhekieltä Any topological space homeomorphic to the region in a plane between two concentric circles of different radius.
puhekieltä The ring of the sun not covered by the moon in an annular eclipse|annular solar eclipse.
puhekieltä Structure in a fern that consists of differentially thick-walled cells on a sporangium that bend and distort as a result of drying.
puhekieltä The membranous remnants of a partial veil which leaves a ring on the stem of a mushroom.
puhekieltä The space contained between the centre well bore and any external tubing. Sometimes used for separated gas flow.
(alternative form of)