com·​plex·​i·​ty | \ kəm-ˈplek-sə-tē How to pronounce complexity (audio) , käm- \
plural complexities

Definition of complexity

1 : something complex the complexities of the murder trial
2 : the quality or state of being complex the complexity of the contract

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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.
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Recent Examples on the Web The five new cases add to the complexities of how the Defense Department should handle people who have previously tested positive for COVID-19. Zachary Halaschak, Washington Examiner, "Five sailors aboard USS Theodore Roosevelt test positive for virus a second time," 15 May 2020 The interviews can take anywhere from 15 minutes to an hour, depending on the complexity of the case. Lauren Caruba,, "How an army of San Antonio students is helping contact trace for the coronavirus," 8 May 2020 But the fact that many people infected with Covid-19 have no or few symptoms could add to the complexity. Helen Branswell, STAT, "Infect volunteers with Covid-19 in the name of research? A proposal lays bare a minefield of issues," 1 May 2020 The order is in place until April 30, but GM has plants in other states with different orders in place, adding to the complexity of a restart, the person said. Jamie L. Lareau, Detroit Free Press, "GM to recall some plant workers next week to prep restart," 23 Apr. 2020 But most people don’t know how to manage money and all the complexities that come with it. Adam Shell, USA TODAY, "Managing finances is complex. Why shouldn't you have a ‘money mentor’ to help?," 26 Mar. 2020 Because of all the complexity, atmospheric weather patterns now become nearly global, although some areas covered by ice sheets don't see much in the way of wind patterns. John Timmer, Ars Technica, "Climate models go out of this world," 2 Mar. 2020 Despite the complexity of the natural world, the research approach to understanding how potentially pandemic pathogens and their animal and human hosts interact has been relatively simple. Alan Rudolph, The Conversation, "Re-creating live-animal markets in the lab lets researchers see how pathogens like coronavirus jump species," 6 Feb. 2020 Despite the complexity and differing ideas on reparations, Kunnecke said there is no excuse for inaction. Billy Kobin, The Courier-Journal, "Ahead of MLK Day, attendees at Archdiocese of Louisville event urge action on reparations," 18 Jan. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'complexity.' 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 complexity

1661, in the meaning defined at sense 1

History and Etymology for complexity

see complex entry 2

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Time Traveler for complexity

Time Traveler

The first known use of complexity was in 1661

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Statistics for complexity

Last Updated

22 May 2020

Cite this Entry

“Complexity.” Dictionary, Merriam-Webster, Accessed 28 May. 2020.

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More Definitions for complexity


How to pronounce complexity (audio)

English Language Learners Definition of complexity

: the quality or state of not being simple : the quality or state of being complex
: a part of something that is complicated or hard to understand


com·​plex·​i·​ty | \ kəm-ˈplek-sə-tē How to pronounce complexity (audio) \
plural complexities

Kids Definition of complexity

1 : the quality or condition of being difficult to understand or of lacking simplicity the complexity of a problem
2 : something difficult to understand or lacking simplicity the complexities of business

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Comments on complexity

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