Chiasma :: Chiasma (n.) A commissure; especially, the optic commissure, or crucial union of the optic nerves..
Chiasmus :: Chiasmus (n.) An inversion of the order of words or phrases, when repeated or subsequently referred to in a sentence.
Chiastolite :: Chiastolite (n.) A variety of andalusite; -- called also macle. The tessellated appearance of a cross section is due to the symmetrical arrangement of impurities in the crystal.
Trichiasis :: Trichiasis (n.) A disease of the eye, in which the eyelashes, being turned in upon the eyeball, produce constant irritation by the motion of the lids..