(1):

(n.) The act of polarizing; the state of being polarized, or of having polarity.

(2):

(n.) An effect produced upon the plates of a voltaic battery, or the electrodes in an electrolytic cell, by the deposition upon them of the gases liberated by the action of the current. It is chiefly due to the hydrogen, and results in an increase of the resistance, and the setting up of an opposing electro-motive force, both of which tend materially to weaken the current of the battery, or that passing through the cell.

(3):

(n.) A peculiar affection or condition of the rays of light or heat, in consequence of which they exhibit different properties in different directions.