cosmos

American  

[koz-mohs, -muhs] / ˈkɒz moʊs, -məs /

noun

plural

cosmos, cosmoses

1. the world or universe regarded as an orderly, harmonious system.

2. a complete, orderly, harmonious system.

3. order; harmony.

4. any composite plant of the genus Cosmos, of tropical America, some species of which, as C. bipannatus and C. sulphureus, are cultivated for their showy ray flowers.

5. (initial capital letter) Also Kosmos. one of a long series of Soviet satellites that have been launched into orbit around the earth.

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Cosmos ¹ British  

/ ˈkɒzmɒs /

noun

1. astronautics any of various types of Soviet satellite, including Cosmos 1 (launched 1962) and nearly 2000 subsequent satellites

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cosmos ² British  

/ ˈkɒzmɒs /

noun

1. the world or universe considered as an ordered system

2. any ordered system

3. harmony; order

4. any tropical American plant of the genus Cosmos, cultivated as garden plants for their brightly coloured flowers: family Asteraceae (composites)

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cosmos Scientific  

/ kŏz′məs,kŏz′mōs′ /

1. The universe, especially when considered as an orderly and harmonious whole.

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Usage

What is the cosmos flower? A cosmos is a flower with brightly colored, raylike petals. The name cosmos can be used for any plant in the genus Cosmos. The plural can be cosmos or cosmoses. Cosmoses are popular in gardens. Two of the best-known species are Cosmos bipannatus and Cosmos sulphureus (known as sulphur cosmos), both of which are cultivated for their flowers. Cosmos flowers vary widely in color. Varieties include yellow, orange, pink, and purple. In some varieties, the petals are notched at the tips. Cosmos are one of the October birth flowers (a flower that’s associated with a particular month in the same way as a birthstone). Example: The display at the botanical garden featured flashy orange cosmoses.

Etymology

Origin of cosmos

First recorded in 1150–1200; Middle English, from Greek kósmos “order, form, arrangement, the world or universe”

Explanation

The cosmos is the sum total of everything — pretty big. It's hard to wrap your mind around the cosmos, as it extends far beyond the Milky Way, or far-off galaxies, or even our own universe. Cosmos is originally a Greek word, meaning both "order" and "world," because the ancient Greeks thought that the world was perfectly harmonious and impeccably put in order. We now use cosmos without the idea of perfect order. Now it means, "all of creation," and particularly on the scale of the stars, the planets, the black holes, the other universes, and all the stuff we don't know about. It's also, totally separately, the name of a pretty, flowering Mexican herb.

Example Sentences

More than 2,000 years ago, a debate raged between atomist philosophers—who thought the cosmos comprised infinite atoms, arranged into infinite worlds, some inhabited like ours—and those who believed Earth was unique.

From The Wall Street Journal • Apr. 23, 2026

Time and again, the missions that matter most put a human face on the cosmos, allowing those watching from Earth to feel they too were along for the ride.

From BBC • Apr. 16, 2026

Their vibrant, jam-packed settings depict anything from an oceanic rave to a rainbow-hued big top performance to a joyride through the cosmos.

From Los Angeles Times • Mar. 25, 2026

Someone must venture to the far side of the cosmos to investigate whatever factor is stopping the solar Pac-Man out there, in hopes of bringing it back to our solar system and saving our sun.

From The Wall Street Journal • Mar. 18, 2026

A Clock Watcher whose whole body seemed a shifty cosmos of dark skies, dark clouds, and stars, with a lopsided fingernail moon where most people had faces, raised its arms high and wide.

From "The Last Last-Day-of-Summer" by Lamar Giles

Related Words

• galaxy
• solar system