geometry

noun

ge·​om·​e·​try jē-ˈä-mə-trē 

plural geometries

1

a

: a branch of mathematics that deals with the measurement, properties, and relationships of points, lines, angles, surfaces, and solids

broadly : the study of properties of given elements that remain invariant under specified transformations

b

: a particular type or system of geometry

Euclidean geometry

2

a

: configuration

… the [bicycle] frame's geometry can be adjusted via a two-position lower shock mount which slackens the angles by another half a degree.

—Liam Mercer

b

: surface shape

the geometry of the landscape

The shape of the earbud is tailored to the geometry of your ear.

—Noah Robischon

The Ken Onion also allows you to choose the type of blade geometry for whatever implement you're sharpening …

—Ariel Kanter

Every object naturally resonates when hit by electromagnetic waves of particular frequencies, which are determined by the object's geometry and material properties.

—Ada Poon

3

: an arrangement of objects or parts that suggests geometric figures

the geometry of neoclassical architecture

Synonyms of geometry

• shape
• form

Examples of geometry in a Sentence

the geometry of Sydney's famed opera house is suggestive of some modernistic sailing ship

Recent Examples on the Web

The lawsuit filed by the families names Wilburn, Riverside County, and the cities of Beaumont and Calimesa as defendants, alleging the intersection was dangerously designed and maintained, with inadequate sight lines caused by roadway geometry, vegetation and utility equipment. —Alaa Elassar, CNN Money, 22 June 2026

This year, classes include theology, Latin, anatomy and physiology, algebra, geometry and logic. —Doug Ross, Chicago Tribune, 21 June 2026

So lean into the solstice this week, do some real stargazing and build your confidence gradually while the geometry of Earth's tilt turns in your favor. —Jamie Carter, Space.com, 19 June 2026

Similarly, John Portman’s Entelechy II in Georgia and Ray Kappe’s home in Los Angeles deftly manipulate space and perspective, employing bold geometries and gravity-defying cantilevers to connect airy interiors to the landscape. —Mark David, Robb Report, 18 June 2026

Word History

Etymology

Middle English geometrie, from Anglo-French, from Latin geometria, from Greek geōmetria, from geōmetrein to measure the earth, from geō- ge- + metron measure — more at measure

First Known Use

14th century, in the meaning defined at sense 1a

Phrases Containing geometry

• algebraic geometry
• analytic geometry
• coordinate geometry
• differential geometry
• Euclidean geometry
• plane geometry
• projective geometry
• Riemannian geometry
• solid geometry
• spherical geometry
• synthetic geometry

Rhymes for geometry

• anthropometry
• audiometry
• densitometry
• radiometry
• sociometry
• trigonometry
• cytometry
• manometry
• morphometry
• optometry
• photometry
• spectrometry

Kids Definition

geometry

noun

ge·​om·​e·​try jē-ˈäm-ə-trē 

plural geometries

1

: a branch of mathematics that deals with points, lines, angles, surfaces, and solids

2

: shape entry 2

the geometry of a crystal