cosmology

American  

[koz-mol-uh-jee] / kɒzˈmɒl ə dʒi /

noun

1. the branch of philosophy dealing with the origin and general structure of the universe, with its parts, elements, and laws, and especially with such of its characteristics as space, time, causality, and freedom.

2. the branch of astronomy that deals with the general structure and evolution of the universe.

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cosmology British  

/ kɒzˈmɒlədʒɪ, ˌkɒzməˈlɒdʒɪkəl /

noun

1. the philosophical study of the origin and nature of the universe

2. the branch of astronomy concerned with the evolution and structure of the universe

3. a particular account of the origin or structure of the universe

   Ptolemaic cosmology

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cosmology Scientific  

/ kŏz-mŏl′ə-jē /

1. The scientific study of the origin, evolution, and structure of the universe.

2. A specific theory or model of the origin and evolution of the universe.

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cosmology ¹ Cultural  

1. The branch of science dealing with the large-scale structure, origins, and development of the universe. (See astronomy and Big Bang theory.)

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cosmology ² Cultural  

1. A system of beliefs that seeks to describe or explain the origin and structure of the universe. A cosmology attempts to establish an ordered, harmonious framework that integrates time, space, the planets, stars, and other celestial phenomena. In so-called primitive societies, cosmologies help explain the relationship of human beings to the rest of the universe and are therefore closely tied to religious beliefs and practices. In modern industrial societies, cosmologies seek to explain the universe through astronomy and mathematics. Metaphysics also plays a part in the formation of cosmologies. (See also under “Physical Sciences and Mathematics.”)

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Other Word Forms

• cosmologer
  noun
• cosmologic
  adjective
• cosmological
  adjective
• cosmologically
  adverb
• cosmologist
  noun

Etymology

Origin of cosmology

From the New Latin word cosmologia, dating back to 1650–60. See cosmo-, -logy

Compare meaning

How does cosmology compare to similar and commonly confused words? Explore the most common comparisons:

• cosmology vs. cosmogony

Explanation

Cosmology is the study of the cosmos, which is the entire universe. Someone who studies cosmology is interested in the structure, origins, and development of the universe. In cosmology, the major theory of the origin of the universe is the Big Bang Theory, the idea that 12 to 14 billion years ago, a small amount of hot, dense matter began expanding, eventually cooling and forming the stars and galaxies we know today. Cosmos comes from the Greek word kosmos, which means world or universe, and cosmology comes from cosmos. Don't confuse cosmology with cosmetology, which is the study of beauty treatments.

Example Sentences

Modern cosmology is often associated with massive observatories, advanced instruments, and large international collaborations backed by significant funding.

From Science Daily • Apr. 27, 2026

The other looks much farther back in time, using the cosmic microwave background to estimate what the expansion rate should be today based on the standard model of cosmology.

From Science Daily • Apr. 12, 2026

Astronomers may be getting closer to understanding one of the biggest mysteries in cosmology: dark energy, the unknown force believed to be driving the accelerating expansion of the universe.

From Science Daily • Mar. 16, 2026

“There’s that side of me that really gets excited about looking at those objects, then creating my own sort of cosmology, my own artifacts, if you will,” she said.

From Los Angeles Times • Dec. 30, 2025

This red shift, observed in the spectral lines of distant galaxies and interpreted as a Doppler effect, is the key to cosmology.

From "Cosmos" by Carl Sagan

Related Words

• creation