Originally: a condition in which a person is unable to determine on which side of the body a stimulus has been applied. In later use: specifically a condition in which a stimulus applied or presented to one side of the body is perceived as occurring on the opposite side.
Allochiria has been reported in various conditions affecting the brain and spinal cord, especially in association with lesions affecting the right parietal lobe, and in hysteria.
Late 19th century. From German Allocheirie from German allo- + ancient Greek χείρ hand + German -ie.