<p><strong>Noun</strong></p><ul><li>the correspondence in size, form, and arrangement of parts on opposite sides of a plane, line, or point; regularity of form or arrangement in terms of like, reciprocal, or corresponding parts.</li><li>the proper or due proportion of the parts of a body or whole to one another with regard to size and form; excellence of proportion.</li><li>beauty based on or characterized by such excellence of proportion.</li><li>a geometrical or other regularity that is possessed by a mathematical object and is characterized by the operations that leave the object invariant.</li><li>a property of a physical system that is unaffected by certain mathematical transformations.</li></ul>