definition of
symmetry

[1] #1 symmetry n. [symmetricalness, correspondence, balance] (mathematics) an attribute of a shape or relation; exact reflection of form on opposite sides of a dividing line or plane. wn

[2] #2 symmetry n. [proportion] balance among the parts of something. wn

[3] #3 symmetry n. [isotropy] (physics) the property of being isotropic; having the same value when measured in different directions. wn