syzygy
sy·zygy
noun
1.
the straight line configuration of 3 celestial bodies (as the sun and earth and moon) in a gravitational system
Origin
From Late Latin sȳzygia (“a conjunction”), from Ancient Greek συζυγία (suzugía, “a union, a yoke, a pair”). This word was recognized as English in 1847 (in its astronomical meaning).
Related words
Broader terms
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.