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

Each of the 22 rays is represented in the primary somatosensory cortex by a distinct morphological module — a stripe of tissue identifiable under cytochrome oxidase staining, arranged in a pattern that mirrors the star’s geometry. —Scott Travers, Forbes.com, 20 May 2026

Instead of relying on traditional geometry tricks, the AI connected the problem to algebraic number theory, a deep branch of mathematics that studies number systems extending ordinary integers. —Aamir Khollam, Interesting Engineering, 20 May 2026

In a news release shared Wednesday, Paxton says that Meta Glasses are able to use cameras, speakers, and other components to capture data, including video and audio recordings and peoples' facial geometry. —Matthew Ablon, CBS News, 20 May 2026

But the resolution to Poincaré’s confusion would come not from geometry, but from a nascent branch of logic called set theory. —Konstantin Kakaes, Quanta Magazine, 20 May 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