gyre

1. A circular or spiral form; a vortex: "rain swirling the night into tunnels and gyres" (Anthony Hyde).
2. A circular or spiral motion, especially a circular ocean current.

[Latin gȳrus, from Greek gūros.]

noun

A closed plane curve everywhere equidistant from a fixed point or something shaped like this: band¹, circle, circuit, disk, ring¹, wheel. Archaic orb. See geometry.

A large water-circulation system of geostrophic currents, rotating clockwise in the Northern Hemisphere, or counterclockwise in the Southern Hemisphere.

gyre, a symbol and concept in W. B. Yeats's later writing and thought. The gyre is a circling movement beginning at the tip of a cone and expanding to the broad end; it then reverses and contracts back, changing the direction of spin, or pern, as it does so. Yeats thought of reality as two such cones interpenetrating one another.