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
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:
Finally, one of my favorite poetic and rhetorical tricks is the chiasma.
ANS is largely under hypothalamic control which is situated very close to optic chiasma sixth chakra or ajna chakra.
 He impressed him as a chiasma, i.e., in the form of the letter ch upon the universe.
It is enough to induce chromosome breakage should the terminalization process be blocked before the terminalizing chiasma reaches the end of the arm of a chromosome.
A chiasma so located starts its terminalization process to reach the end of the arm.
The fibers thus form an X shape; and the structure is the optic chiasma (ky~az'muh), because the Greek letter "chi" looks like our X (see illustration, p. 274).
In front, the cisterna interpeduncularis extends forward across the optic chiasma, forming the cisterna chiasmatis, and on to the upper surface of the corpus callosum, for the arachnoid stretches across from one cerebral hemisphere to the other immediately beneath the free border of the falx cerebri, and thus leaves a space in which the anterior cerebral arteries are contained.