— chiasmal, chiasmic, chiasmatic /kuy'az mat"ik/ , adj.
/kuy az"meuh/ , n. , pl. chiasmas, chiasmata /-meuh teuh/ .
1. Anat. a crossing or decussation, as that of the optic nerves at the base of the brain.
2. Cell Biol. a point of overlap of paired chromatids at which fusion and exchange of genetic material take place during prophase of meiosis.
Also, chiasm /kuy"az euhm/ .
[ 1830-40; chi CHI 1 + -asma n. suffix ]