Definition of "syzygy"

syzygy

/ˈsɪz.ɪ.d͡ʒi/

noun
countable and uncountable, plural syzygies
1. (astronomy, astrology) An alignment of three celestial bodies (for example, the Sun, Earth, and Moon) such that one body is directly between the other two, such as occurs at an eclipse.
  Quotations
  The duration of an eclipse depends on the relative positions of the sun, moon, and earth in their syzygy.
  2004, Phyllis M. Lugger, William Liller, Asteroids to Quasars: A Symposium Honoring William Liller, Cambridge University Press, page 67
2. (Jungian psychology) An archetypal pairing of contrasexual opposites, symbolizing the communication of the conscious and unconscious minds.
  Quotations
  In 1936 Jung defends his concept of animus and anima by reference to the idea of the syzygy, concluding from the evidence in many different mythologies of the divine couple, united by a sacred marriage, that this motif is as universal as the existence of men and women. He postulates that in the syzygy the archetypal union of the parents is expressed, the mother corresponding to the anima.
  2006, Renos K. Papadopoulos, The Handbook of Jungian Psychology: Theory, Practice and Applications, Psychology Press, page 117
3. (mathematics, linear algebra) A relation between generators of a module.
  Quotations
  A finitely presented module is an A-module M given by a finite number of generators and relations. Therefore it is a module with a finite generator set having a finitely generated syzygy module.
  2015, Henri Lombardi, Claude Quitté, Commutative Algebra: Constructive Methods: Finite Projective Modules, Springer, page 173
4. (medicine) The fusion of some or all of the organs.
5. (zoology) The association of two protozoa end-to-end or laterally for the purpose of asexual exchange of genetic material.
  Quotations
  When two or more arm-joints meet transversely by a rigid suture, and only the upper one is pinnule-bearing, those joints form a syzygy, whether their apposed faces are striated, dotted, or smooth.
  1900, Karl Alfred von Zittel, Text-book of Paleontology: Protozoa. Coelentrata (zoophytes). Echinodermata. Vermes (Worms). Molluscoidea. Mollusca. Arthropoda (articulates)
  These include syzygy, fusion of larvae or adults of flatworms, fusion of buds of some Tunicata, somatic fertilization (fusion of spermatozoa with somatic cells), composite zygotes of some Cestoda and Insecta, and fusion of cells in various tissues.
  2018, Richard E. Blackwelder, The Diversity of Animal Reproduction, CRC Press
6. (genetics) The pairing of chromosomes in meiosis.