1. The correspondence of the form and arrangement of elements or parts on opposite sides of a dividing line or plane or about a center or an axis:the symmetry of a butterfly's wings.
2. A relationship in which there is correspondence or similarity between entities or parts:the symmetry of the play, which opens and ends with a speech by a female character.
3. Beauty as a result of pleasing proportions or harmonious arrangement:"Here were the ringlets, framing a face of exquisite symmetry"(Clive Barker).
4. Physics Invariance under transformation. For example, a system that is invariant under rotation has rotational symmetry.
[Latinsymmetria, fromGreeksummetriā, fromsummetros, of like measure : sun-, syn- + metron, measure; see mē-2 in the Appendix of Indo-European roots.]
(click for a larger image)symmetry
top: bilateral symmetry
bottom: radial symmetry
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus