symmetry

noun

sym·​me·​try ˈsi-mə-trē 

plural symmetries

1

: balanced proportions

also : beauty of form arising from balanced proportions

2

: the property of being symmetrical

especially : correspondence in size, shape, and relative position of parts on opposite sides of a dividing line or median plane or about a center or axis compare bilateral symmetry, radial symmetry

3

: a rigid motion of a geometric figure that determines a one-to-one mapping onto itself

4

: the property of remaining invariant under certain changes (as of orientation in space, of the sign of the electric charge, of parity, or of the direction of time flow)

—used of physical phenomena and of equations describing them

Synonyms of symmetry

• proportion
• harmony
• balance
• orchestration
• correlation
• unity
• coherence
• equilibrium

Examples of symmetry in a Sentence

the symmetry of the human body

The building has perfect symmetry.

Recent Examples on the Web

The idea of Noah playing Hamlet — opposite Jacobi’s Hamnet — brought an unexpected emotional symmetry to the film. —Mia Galuppo, HollywoodReporter, 20 Nov. 2025

To counter that challenge, Quiroz and William Watkins, a physics graduate student at Johns Hopkins, turned to symmetry, a mathematical property that helps simplify complex structures. —Aamir Khollam, Interesting Engineering, 20 Nov. 2025

The difference lies in the logic of power symmetry. —Deng Yuwen, Foreign Affairs, 14 Nov. 2025

As the explosion grew larger and smacked into nearby matter, the shape started flattening while the ejecta’s axis of symmetry remained stable. —Andrew Paul, Popular Science, 13 Nov. 2025

Word History

Etymology

Latin symmetria, from Greek, from symmetros symmetrical, from syn- + metron measure — more at measure

First Known Use

1563, in the meaning defined at sense 1

Phrases Containing symmetry

• bilateral symmetry
• center of symmetry
• radial symmetry

Rhymes for symmetry

• altimetry
• asymmetry
• dosimetry
• calorimetry
• colorimetry
• supersymmetry

Kids Definition

symmetry

noun

sym·​me·​try ˈsim-ə-trē 

plural symmetries

1

: balanced proportions

2

: close agreement in size, shape, and relative position of parts on opposite sides of a dividing line or plane or around a central point compare bilateral symmetry, radial symmetry

Medical Definition

symmetry

noun

sym·​me·​try ˈsim-ə-trē 

plural symmetries

1

: correspondence in size, shape, and relative position of parts on opposite sides of a dividing line or median plane or about a center or axis see bilateral symmetry, radial symmetry

2

: the property of remaining invariant under certain changes (as of orientation in space, of the sign of the electric charge, of parity, or of the direction of time flow)

—used of physical phenomena and of equations describing them