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 symmetry of the timelines is gorgeous — something as simple as a cut from India Amarteifio, playing the younger Clarissa, to you. — David Canfield, HollywoodReporter, 10 Sep. 2026

So the apartment offers a rather nice bit of historical symmetry, a home inside a building tied to Norway’s wartime presence in London, overlooking a Christmas tradition that grew out of that same relationship. — Abby Montanez, Robb Report, 10 Sep. 2026

From there, Langlands conjectured the existence of a family of correspondences between objects, symmetries, and properties. — Quanta Magazine, 9 Sep. 2026

For Kennedy, the night also carried extra weight because of the sisters’ 10-year age gap and the unusual symmetry in their story. — Ashley Vega, PEOPLE, 9 Sep. 2026

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