cos·​mos ˈkäz-məs How to pronounce cosmos (audio)
 senses 1 & 2 also  -ˌmōs,
-ˌmäs How to pronounce cosmos (audio)
: an orderly harmonious systematic universe compare chaos
: a complex orderly self-inclusive system
plural cosmos ˈkäz-məs How to pronounce cosmos (audio)
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 This week is the Perseids’ week—an annual gift from a cosmos that most of us will never touch, but that all of us can see and celebrate. Jeffrey Kluger, Time, 11 Aug. 2023 Posey can conjure an entire cosmos in a tiny, swarming square. Mark Jenkins, Washington Post, 16 June 2023 The answers to many cosmological mysteries—the nature of dark energy, the properties of the ancient cosmos, and more—live inside the voids. Popular Mechanics, 6 June 2023 What are your top plant recommendations for a home gardener looking to start growing their own cake decor? Flowers: Sunflowers, cosmos, and passionfruit. Kristin Guy, Sunset Magazine, 16 Mar. 2023 Here are three highlights from Universal Harmonies, each of them bringing to life one facet of our dynamic cosmos. Dan Falk, Smithsonian Magazine, 1 Mar. 2023 A number of these suggest an energized, explosive cosmos: darkness suffused with light. Vince Aletti, The New Yorker, 22 Dec. 2022 Their dominant shapes are pristine and eternal, but those perfect circles are lapped by blobs, blotches and squiggles that represent a cosmos in constant flux. Mark Jenkins, Washington Post, 13 Jan. 2023 Perhaps our cosmos, complete with our hundred billion stars per galaxy and the hundred billion galaxies in the observable universe, is nothing more than a snow globe on some alien creature’s mantel. Neil Degrasse Tyson, WSJ, 17 Sep. 2022 See More

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

Word History


Greek kosmos

First Known Use

1596, in the meaning defined at sense 1a

Time Traveler
The first known use of cosmos was in 1596

Dictionary Entries Near cosmos

Cite this Entry

“Cosmos.” Dictionary, Merriam-Webster, Accessed 28 Nov. 2023.

Kids Definition


cos·​mos ˈkäz-məs How to pronounce cosmos (audio)
senses 1 & 2 also
-ˌmōs How to pronounce cosmos (audio)
: the orderly universe
: a complex harmonious system
: a tall garden plant that is related to the daisies and has showy white, pink, or rose-colored flower heads with usually yellow centers

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