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

Many of those who study planetary geology have likened Mars’s surface material to the fresh volcanic, basaltic soils found in Hawaii. —Big Think, 6 Nov. 2025

The notion that the same basic processes of geology and chemistry apply beyond Earth, that mineral-bearing asteroids, ice-rich objects, and lunar regolith may host economically valuable materials, has increasingly garnered technical and commercial attention. —Kaif Shaikh, Interesting Engineering, 5 Nov. 2025

Unique to this project, Xcel Energy has also engaged a geological consultant to conduct an investigation of the project area’s geology and to develop a comprehensive karst management plan, including a response protocol if karst geologic features are encountered. —Elliot Mann, Twin Cities, 5 Nov. 2025

Interested in more geology episodes? —Berly McCoy, NPR, 4 Nov. 2025

Word History

Etymology

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

First Known Use

1735, in the meaning defined at sense 1a

Rhymes for geology

• anthology
• apology
• astrology
• biology
• christology
• chronology
• conchology
• cosmology
• cryptology
• cytology
• doxology
• ecology

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