from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. Anatomy A crossing or intersection of two tracts, as of nerves or ligaments.
  • n. Genetics The point of contact between paired chromatids during meiosis, resulting in a cross-shaped configuration and representing the cytological manifestation of crossing over.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A crossing of two nerves, ligaments etc.
  • n. The contact point between the two chromatids of a chromosome during meiosis.

from The Century Dictionary and Cyclopedia

  • n. Same as chiasm.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. an intersection or crossing of two tracts in the form of the letter X


Greek khīasma, cross-piece, from khīazein, to mark with an X, from khei, khī, chi (from the letter's shape).
(American Heritage® Dictionary of the English Language, Fourth Edition)
Modern Latin, from Ancient Greek χίασμα, from χίαζειν ("to mark with the letter chi"). (Wiktionary)


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