cos·​mol·​o·​gy käz-ˈmä-lə-jē How to pronounce cosmology (audio)
plural cosmologies
: a branch of metaphysics that deals with the nature of the universe
: a theory or doctrine describing the natural order of the universe
: 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 adjective
cosmologically adverb
cosmologist noun

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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 In the latest models of cosmology, these unobserved phenomena make up 95 percent of the universe. Kate Larue, New York Times, 5 Nov. 2023 The sprawling event will boast 60 exhibitions and more than 800 artists exploring topics such as ancient cosmology, artificial intelligence, Indigenous science fiction and environmental justice. Jessica Gelt, Los Angeles Times, 31 Oct. 2023 In the Shadow of Quetzalcoatl: Zelia Nuttall and the Search for Mexico’s Ancient Civilizations The gripping story of a pioneering anthropologist whose exploration of Aztec cosmology, rediscovery of ancient texts, and passion for collecting helped shape our understanding of pre-Columbian Mexico. Merilee Grindle, Smithsonian Magazine, 23 Oct. 2023 The concert is punctuated with visuals that offer a sense of Beyoncé’s cosmology: graphics of her soaring through expansive galaxies, including a winged robotic version of the singer astride a rocket navigating outer space. Jenna Wortham, New York Times, 27 Sep. 2023 Political legitimacy was a mixture of cosmology—the emperor as the Son of Heaven, who was mandated by Heaven to rule the earth—and moral doctrines based on Confucian philosophy. Ian Buruma, The New Yorker, 25 Sep. 2023 The signal appears in the polarization, or orientation, of CMB light waves, which the standard model of cosmology says should remain constant on the waves’ journey across the universe. Zack Savitsky, Quanta Magazine, 13 Mar. 2023 In its irreverent cosmology, the sacred is inseparable from the mundane, profundity from comedy, spiritual sustenance from junk food. James Poniewozik, New York Times, 27 Sep. 2023 The theory, which quickly became dominant in cosmology circles, describes a period of exponential expansion at the beginning of time. Gabe Allen, Discover Magazine, 17 Feb. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'cosmology.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

First Known Use

circa 1656, in the meaning defined at sense 1a

Time Traveler
The first known use of cosmology was circa 1656

Dictionary Entries Near cosmology

Cite this Entry

“Cosmology.” Dictionary, Merriam-Webster, Accessed 30 Nov. 2023.

Kids Definition


cos·​mol·​o·​gy käz-ˈmäl-ə-jē How to pronounce cosmology (audio)
plural cosmologies
: a branch of astronomy that deals with the beginning, structure, and space-time relationships of the universe
cosmologist noun

More from Merriam-Webster on cosmology

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