noun. A crossing or intersection of two tracts, as of nerves or ligaments.

noun. The point of contact between paired chromatids during meiosis, resulting in a cross-shaped configuration and representing the cytological manifestation of crossing over.

noun. Same as chiasm.

noun. A crossing of two nerves, ligaments etc.

noun. The contact point between the two chromatids of a chromosome during meiosis.

noun. 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."

optic chiasma  

SMA  chiasm  neuritis  optician  thalami  

chiasmata