geology

noun

ge·​ol·​o·​gy jē-ˈä-lə-jē 

plural geologies

1

a

: a science that deals with the history of the earth and its life especially as recorded in rocks

b

: a study of the solid matter of a celestial body (such as the moon)

2

: geologic features

the geology of Arizona

3

: a treatise on geology

geologist

jē-ˈä-lə-jist 

noun

Examples of geology in a Sentence

learning about the geology of Hawaii

Recent Examples on the Web

Further evidence gathered by both the Mars Reconnaissance Orbiter, a satellite that probes Mars’s surface for clues to its current and past geology, and NASA’s Perseverance rover suggests the planet also has material made up of crystals of hydrated silica—a mineral better known on Earth as opal. —Adam Kovac, Scientific American, 12 May 2026

Plentiful rain falling on porous karst geology collects and feeds groundwater to more than 300 artesian springs. —Robert Knight, The Orlando Sentinel, 8 May 2026

Artificial intelligence could help close that gap, but only if it is built for the realities of geology and mining. —Nia Bowers, USA Today, 8 May 2026

Limnology and geology Thoreau also pioneered limnology, the science of lakes. —Robert M. Thorson, The Conversation, 8 May 2026

Word History

Etymology

New Latin geologia, from ge- + -logia -logy

First Known Use

1735, in the meaning defined at sense 1a

Rhymes for geology

• ology
• aetiology
• anthropology
• archaeology
• archeology
• audiology
• cardiology
• climatology
• cohomology
• cosmetology
• criminology
• demonology

Kids Definition

geology

noun

ge·​ol·​o·​gy jē-ˈäl-ə-jē 

plural geologies

1

a

: a science that deals with the history of the earth and its life especially as recorded in rocks

b

: a study of the features of a heavenly body (as the moon)

2

: the geologic features (as mountains or plains) of an area

geologic

ˌjē-ə-ˈläj-ik

adjective

or geological

-i-kəl

geologically

-i-k(ə-)lē

adverb

geologist

jē-ˈäl-ə-jəst 

noun