complexity

noun

com·plex·i·ty kəm-ˈplek-sə-tē

käm-

plural complexities

Synonyms of complexity

: something complex

the complexities of the murder trial

: the quality or state of being complex

the complexity of the contract

Examples of complexity in a Sentence

He was impressed by the complexity of the music. The diagram illustrates the complexity of the cell's structure. He doesn't grasp the complexity of the situation.

Recent Examples on the Web

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

On the big-picture scale, scientists have used the planetary boundaries framework to capture the complexity of the Earth’s systems, and the impact of climate change on all of them. — Bella Webb, Vogue, 29 Oct. 2026 But Idaho physicians told the Statesman that those exceptions often do not exist in practice — in large part because legal language is ill-suited to capture the complexities of medical care. — Sarah Cutler, Idaho Statesman, 29 Oct. 2026 What readers are saying The conversation explores the complexities and controversies surrounding a rancher's decision to sell shares of his cattle herd, which led to regulatory scrutiny. — Abby Shalekbriski, Washington Post, 28 Oct. 2026 The Lilliputians are as small-minded as their size and conduct querulous, violent debates about which end of an egg to crack (so obviously similar to the theological complexities of Swift’s own day). — Literary Hub, 28 Oct. 2026 See All Example Sentences for complexity

Word History

Etymology

complex entry 2 + -ity, perhaps after French complexité

First Known Use

1661, in the meaning defined at sense 1

Time Traveler

The first known use of complexity was in 1661

See more words from the same year

Cite this Entry

Style

“Complexity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/complexity. Accessed 1 Nov. 2026.

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Kids Definition

complexity

noun

com·plex·i·ty kəm-ˈplek-sət-ē

käm-

plural complexities

: something complex

the complexities of the English language

: the quality or state of being complex

complexity

noun

Synonyms of complexity

Examples of complexity in a Sentence

Word History

Browse Nearby Words

Cite this Entry

Kids Definition

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complexity

noun

Synonyms of complexity

Examples of complexity in a Sentence

Word History

Rhymes for complexity

Browse Nearby Words

Cite this Entry

Kids Definition

More from Merriam-Webster on complexity

More from Merriam-Webster

Word of the Day

Pyrrhic

Popular in Grammar & Usage

How to Use 'Who' vs. 'Whom'

Merriam-Webster’s Great Big List of Words You Love to Hate

'Affect' vs. 'Effect'

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?

Popular in Wordplay

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

Pwn, Skibidi, Girlboss and Other Words Added to the 2026 Scrabble Dictionary

The Words of the Week - Oct. 30

12 Lovely and Unusual Words for the Natural World

Popular

How to Use 'Who' vs. 'Whom'

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

Games & Quizzes