*polarity*

n. [ Cf. F. polarité. ] 1. (Physics) That quality or condition of a body in virtue of which it exhibits opposite, or contrasted, properties or powers, in opposite, or contrasted, parts or directions; or a condition giving rise to a contrast of properties corresponding to a contrast of positions, as, for example, attraction and repulsion in the opposite parts of a magnet, the dissimilar phenomena corresponding to the different sides of a polarized ray of light, etc. [ 1913 Webster ]

2. (Geom.) A property of the conic sections by virtue of which a given point determines a corresponding right line and a given right line determines a corresponding point. See Polar, n. [ 1913 Webster ]