chiasm

2 definitions found

chiasm - Collaborative International Dictionary of English v.0.48 :

  Chiasm \Chi"asm\ (k[imac]"[a^]z'm), Chiasma \Chi*as"ma\
     (k[-i]*[a^]z"m[.a]), n. [NL. chiasma, fr. Gr. chi`asma two
     lines placed crosswise, fr. ? to mark with a [chi].] (Anat.)
     A commissure; an intersection or crossing of two tracts;
     especially, the optic commissure, or crucial union of the
     optic nerves. -- Chi*as"mal, a..
     [1913 Webster] chiasmatic
     chiasmal

chiasm - WordNet (r) 2.1 (2005) :

  chiasm
      n 1: an intersection or crossing of two tracts in the form of
           the letter X [syn: chiasma, chiasm, decussation]