n. pl. syz·y·gies
a. Either of two points in the orbit of a solar system body where the body is in opposition to or in conjunction with the sun.
b. Either of two points in the orbit of the moon when the moon lies in a straight line with the sun and Earth.
c. The configuration of the sun, the moon, and Earth lying in a straight line.
2. The combining of two feet into a single metrical unit in classical prosody.
[Late Latin sȳzygia, from Greek suzugiā, union, from suzugos, paired : sun-, su-, syn- + zugon, yoke; see yeug- in the Appendix of Indo-European roots.]
sy·zygi·al (sĭ-zĭjē-əl) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.