symmetry Meaning, Definition & Usage

  1. noun (mathematics) an attribute of a shape or relation; exact reflection of form on opposite sides of a dividing line or plane
    symmetricalness; correspondence; balance.
  2. noun balance among the parts of something
    proportion.
  3. noun (physics) the property of being isotropic; having the same value when measured in different directions
    isotropy.

WordNet

Sym"me*try noun
Etymology
L. symmetria, Gr. with, together + a measure: cf. F. symétrie. See Syn-, and Meter rhythm.
Definitions
  1. A due proportion of the several parts of a body to each other; adaptation of the form or dimensions of the several parts of a thing to each other; the union and conformity of the members of a work to the whole.
  2. (Biol.) The law of likeness; similarity of structure; regularity in form and arrangement; orderly and similar distribution of parts, such that an animal may be divided into parts which are structurally symmetrical. ✍ Bilateral symmetry, or two-sidedness, in vertebrates, etc., is that in which the body can be divided into symmetrical halves by a vertical plane passing through the middle; radial symmetry, as in echinoderms, is that in which the individual parts are arranged symmetrically around a central axis; serial symmetry, or zonal symmetry, as in earthworms, is that in which the segments or metameres of the body are disposed in a zonal manner one after the other in a longitudinal axis. This last is sometimes called metamerism.
  3. (Bot.) (a) Equality in the number of parts of the successive circles in a flower. (b) Likeness in the form and size of floral organs of the same kind; regularity.

Webster 1913