cos·​mos | \ ˈkäz-məs How to pronounce cosmos (audio) , senses 1 & 2 also -ˌmōs, -ˌmäs How to pronounce cosmos (audio) \

Definition of cosmos

b(1) : an orderly harmonious systematic universe — compare chaos
(2) : order, harmony
2 : a complex orderly self-inclusive system
3 plural cosmos\ ˈkäz-​məs How to pronounce cosmos (audio) , -​məz \ also cosmoses\ ˈkäz-​mə-​səz How to pronounce cosmos (audio) \ [New Latin, genus name, from Greek kosmos] : any of a genus (Cosmos) of tropical American composite herbs especially : a widely cultivated tall annual (C. bipinnatus) with yellow or red disks and showy ray flowers

Illustration of cosmos

Illustration of cosmos

cosmos 3

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Cosmos and the Universe

Cosmos often simply means "universe". But the word is generally used to suggest an orderly or harmonious universe, as it was originally used by Pythagoras in the 6th century B.C. Thus, a religious mystic may help put us in touch with the cosmos, and so may a physicist. The same is often true of the adjective cosmic: Cosmic rays (really particles rather than rays) bombard us from outer space, but cosmic questions come from human attempts to find order in the universe.

Examples of cosmos in a Sentence

the origins of the cosmos an essay that ponders the place of humankind in the vast cosmos
Recent Examples on the Web Tyson, Director of New York City’s Hayden Planetarium at the American Museum of Natural History, is well known for his ability to provoke the public into thinking harder about our place in the cosmos. Bruce Dorminey, Forbes, "Provocative New Neil DeGrasse Tyson Book Highlights Little-Known Cosmic Tidbits," 18 Mar. 2021 There is little doubt that our capacity to sense the most ethereal, fleeting phenomena in the cosmos is at an all time high. Caleb A. Scharf, Scientific American, "Until Recently, People Accepted the 'Fact' of Aliens in the Solar System," 21 Feb. 2021 The cosmos, including our small piece of it, would not be the same without them. Marina Koren, The Atlantic, "This Black Hole Was Hiding a Massive Surprise," 4 Mar. 2021 Still, there seems to be no escaping life — or the cosmos. Rebecca Coffey, Forbes, "How Cosmic Rays Help Scientists Tell How Old Dead Stuff Is: An Exuberant, Plain Language Primer On Radiocarbon Dating, in 20 Facts," 3 Mar. 2021 But then again, why not just leave the cosmos and Manolo’s in the past and create something new? Anne Cohen,, "HBO May Be Rebooting Sex & The City — But Don’t Expect Samantha," 24 Dec. 2020 More recently, the spirit of aether has even come back into the discussion of the cosmos, thanks to the mysterious discoveries of dark matter and dark energy, the elusive force believed to be the cause of the accelerating expansion of the universe. Meg Neal, Popular Mechanics, "The Eternal Quest for Aether, the Cosmic Stuff That Never Was," 10 Feb. 2021 Made of bronze, the artifact was inlaid in gold with an ancient vision of the cosmos by its crafters. New York Times, "A Bitter Archaeological Feud Over an Ancient Vision of the Cosmos," 19 Jan. 2021 Some turned out to come from previously unknown astronomical sources such as pulsars, the rapidly rotating corpses of dead stars that beam radio waves into the cosmos. Nadia Drake, Science, "Alien hunters detect mysterious radio signal from nearby star," 18 Dec. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cosmos.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of cosmos

1596, in the meaning defined at sense 1a

History and Etymology for cosmos

Greek kosmos

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Statistics for cosmos

Last Updated

13 Apr 2021

Cite this Entry

“Cosmos.” Dictionary, Merriam-Webster, Accessed 14 Apr. 2021.

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More Definitions for cosmos



English Language Learners Definition of cosmos

: the universe especially when it is understood as an ordered system
: a tall plant that has usually white, pink, or red flowers


cos·​mos | \ ˈkäz-məs, 1 is also -ˌmōs, -ˌmäs \

Kids Definition of cosmos

1 : the universe especially as thought of as an orderly system
2 : a tall garden plant related to the daisies that has showy white, pink, or rose-colored flower heads

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