n. The phenomenon, in chemistry, physics and mathematics, in which objects are mirror images of each other, but are not identical.
The Century Dictionary and Cyclopedia
n. In optics, the power possessed by certain crystals and optically active substances of turning the plane of polarization of light to the right or left hand.
Word Usage
"BTW, for me, chirality is much the strongest evidence for common descent, especially when considered with all the basic biochemical structures and processes that are almost universal, with their rare and fascinating exceptions."