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

Scientists believe the geology of Mars may hold valuable clues about past ancient life, and so the robotic vehicles, controlled remotely from Earth, have slowly navigated the rocky terrain to scoop up and collect intriguing samples. —Eric Lagatta, USA Today, 4 Feb. 2026

La Brea Tar Pits and Museum is widely considered world‑famous, especially in paleontology, geology and natural history circles. —Marianne Love, Daily News, 30 Jan. 2026

Supply growth these days is constrained more by choice and infrastructure, and less by geology. —Bryce Erickson, Forbes.com, 29 Jan. 2026

This feature runs right through the Detroit River, linking the geology of Downriver Michigan with Ontario. —Ahmad Bajjey, CBS News, 29 Jan. 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

• 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