Word of the day · 31 July 2026
syzygy
/ˈsɪzɪdʒi/
noun
An alignment of three celestial bodies, such as the sun, Earth and moon.
In a sentence
- A syzygy of sun, Earth and moon brought the total eclipse.
- Spring tides rise when lunar syzygy pulls with the sun.
- She loved the word syzygy almost as much as the night sky.
In an image
Origin
From Greek syzygia (yoke, union, pairing), from syn- (together) and zygon (yoke).
History
Astronomers use syzygy for conjunctions and oppositions that put Earth and another body in line with the sun. New and full moons are familiar cases. The rare word also appears in mathematics and poetry for paired structures. Most readers meet it first through eclipses and spring tides.
Nearby words
alignment · conjunction · eclipse
When sky objects line up and tides or eclipses follow.