Word of the Day:

: the nearly straight-line configuration of three celestial bodies (such as the sun, moon, and earth during a solar or lunar eclipse) in a gravitational system

The full moon and new moon phenomena occur when the earth, sun, and moon are in syzygy.

"Whether you have a three dimensional orrery or a flat blackboard, eclipses are easy to illustrate and understand and occur at the moment of syzygy when the sun, earth and moon are aligned." — Clellie Lynch, The Berkshire Eagle (Pittsfield, Massachusetts), 30 Sept. 2015

More example sentences

At first glance, syzygy appears to be a somewhat singular member of the English language. Despite its appearance, however, it does have etymological ties to a few words in Modern English. Syzygy can be traced to the Greek syzygos ("yoked together"), a combination of syn- ("with, together with") and zygon ("yoke"). Zygon is also the source of zygote ("a cell formed by the union of two gametes") and zygoma, which refers to several bones and processes of the skull, including the zygomatic bone (a.k.a., the cheekbone). Zygon is also related to the Old English geoc—the source of the Modern English yoke—and the Latin jungere, from which the English words join and junction are derived.