cosmology

noun

cos·​mol·​o·​gy käz-ˈmä-lə-jē 

plural cosmologies

1

a

: a branch of metaphysics that deals with the nature of the universe

b

: a theory or doctrine describing the natural order of the universe

2

: a branch of astronomy that deals with the origin, structure, and space-time relationships of the universe

also : a theory dealing with these matters

cosmological

ˌkäz-mə-ˈlä-ji-kəl 

adjective

cosmologically

ˌkäz-mə-ˈlä-ji-k(ə-)lē 

adverb

cosmologist

käz-ˈmä-lə-jist 

noun

Did you know?

Cosmology and Star Trek

Most religions and cultures include some kind of cosmology to explain the nature of the universe. In modern astronomy, the leading cosmology is still the Big Bang theory, which claims that the universe began with a huge explosion that sent matter and energy spreading out in all directions. One reason why fans watch Star Trek is for the various cosmologies depicted in the show, including different conceptions of space, time, and the meaning of life.

Examples of cosmology in a Sentence

Recent Examples on the Web

His research explores subjects like gravitational physics, dark matter, dark energy and observational cosmology, according to Harvard's website. — Ashley Capoot, CNBC, 21 Oct. 2026

Stubbs later headed the ESSENCE supernova cosmology project which gathered further evidence on the nature of dark energy. — Jeremy Kahn, Fortune, 21 Oct. 2026

Although inflation is a central part of modern cosmology, the physics that drove it remains uncertain. — Kaif Shaikh, Interesting Engineering, 20 Oct. 2026

One of cosmology’s greatest mysteries is the nature of dark energy—the invisible force that keeps the universe expanding at an ever-increasing rate. — Jeffrey Kluger, Time, 15 Oct. 2026

Word History

Etymology

New Latin cosmologia, from Greek kosmos — see cosmic + New Latin -logia -logy

First Known Use

circa 1656, in the meaning defined at sense 1a

Rhymes for cosmology

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

Kids Definition

cosmology

noun

cos·​mol·​o·​gy käz-ˈmäl-ə-jē 

plural cosmologies

: a branch of astronomy that deals with the beginning, structure, and space-time relationships of the universe

cosmologist

-jəst 

noun