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

In their study, the team showed that combining two compounds with nearly identical chemical compositions but different crystal symmetries can yield an entirely new structure type. —Neetika Walter, Interesting Engineering, 9 Dec. 2025

The crater is surrounded by twin lobes of material that fan out to the north and south, evoking the delicate symmetry of a butterfly's wings. —Kenna Hughes-Castleberry, Space.com, 5 Dec. 2025

But, don’t give in just because an artificial tree promises perfect symmetry, low maintenance, no mess, and pre-strung lights. —Megan Schrader, Denver Post, 5 Dec. 2025

In fact, all the fundamental forces in physics — gravity, electromagnetism, and the forces that hold together atomic nuclei — are defined by Lie group symmetries. —Leila Sloman, Quanta Magazine, 3 Dec. 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