Annulus

anillo

(ring- or donut-shaped area or structure)

anillo

(remnants of a partial veil which leaves a ring on the stem of a mushroom)

annulus

(region in a plane between two concentric circles of different radii)

arandela

(region in a plane between two concentric circles of different radii)

corona circular

(region in a plane between two concentric circles of different radii)

corona solar

(ring of light in a celestial body, especially when caused by an annular eclipse)