Definition of "chiasma" []

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

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In this early poem – the first one in his Selected Poems – Heaney uses a rhetoric figure that for a considerable period would be his trademark: the 'chiasma', or crossing of themes."
• "Because the optic chiasma had been cut, using their left eye they were unaware of the left half of the field of view of the screen the virtual image is reversed."
• "Shakespeare's is an interesting line, but a good chiasma is a literary firework -- an "OH!" moment -- and Bill Clinton's delivered a great one Wednesday night:"