Syzygy can refer to any of several different things:

Astronomy

In astronomy, a syzygy (Greek: "yoked together") is a situation where three celestial bodies are positioned along a straight line. The word is usually used in context with the Sun, Earth, and the Moon or a planet, where the latter is in conjunction or opposition. Solar and lunar eclipses are examples of syzygies, as are transits and occultations. The term is also applied to each instance of new moon or full moon when Sun and Moon are in conjunction or opposition even though they are not exactly on one line with the Earth.

The word is also often loosely used to describe interesting configurations of planets in general. For example, situations when all the planets are on the same side of the sun are sometimes called syzygies, although they are not necessarily found along a straight line.

Psychology

In psychology, Carl Gustav Jung used the term syzygy to denote an archetypal pairing of contrasexual opposites, which symbolized the communication of the conscious and unconscious minds.

Mathematics

In mathematics, a syzygy is a relation between the generators of a module. All such relations create what is called the first syzygy module. The relations between generators of the first syzygy module form the second syzygy module. This process can be repeated indefinitely, forming higher-order syzygy modules. See Hilbert's syzygy theorem.

Games

Project Syzygy is an alternate reality game, now referred to as Perplex City . A summary can be found here. For more detailed information, see the Project Syzygy Wiki.

Comics

Syzygy Darklock is a key character in the Space Opera Dreadstar, premier title of Epic Comics. Syzygy is a sort of sorcerer, the founder of the team which stars in that series.

Zoology

• The association of two protozoa end-to-end or lateraly for the purpose of asexual exchange of genetic material.
• The pairing of Chromosomes in Meiosis.