1. A total or partial blocking of light from a celestial body caused by its passing into the shadow of another body; also, the hiding of one celestial body by another one.
2. The obscuring of one celestial body by another one, most notably when the moon passes in front of the sun.

In an eclipse of the sun, it is the light of the sun which is totally or partially cut off from the earth by the moon coming between the two bodies.

1. A solar eclipse in which a ring (an annulus or the figure bounded by and containing the area between two concentric circles) of solar photosphere remains visible.
2. The type of eclipse seen when the moon is too far from the earth at the time of a solar eclipse to completely cover the sun's disk.

The result is a bright ring, or annulus, of light encircling the moon.

The passage of the moon into the earth's shadow.