complex

noun
com·​plex | \ ˈkäm-ˌpleks How to pronounce complex (audio) \

Definition of complex

 (Entry 1 of 3)

1 : a whole made up of complicated or interrelated parts a complex of welfare programs the military-industrial complex
2a : a group of culture traits relating to a single activity (such as hunting), process (such as use of flint), or culture unit
b(1) : a group of repressed desires and memories that exerts a dominating influence upon the personality a guilt complex
(2) : an exaggerated reaction to or preoccupation with a subject or situation He has always had a complex about spiders. She has a weight complex. Not being able to find a job was giving me a complex.
c : a group of obviously related units of which the degree and nature of the relationship is imperfectly known
d : the sum of factors (such as symptoms) characterizing a disease or condition primary tuberculous complex
3 : a chemical association of two or more species (such as ions or molecules) joined usually by weak electrostatic bonds rather than covalent bonds
4 : a building or group of buildings housing related units an apartment complex a sports complex

complex

adjective
com·​plex | \ käm-ˈpleks How to pronounce complex (audio) , kəm-ˈpleks, ˈkäm-ˌpleks \

Definition of complex (Entry 2 of 3)

1a : composed of two or more parts : composite a complex mixture of chemicals
b(1) of a word : having a bound form as one or more of its immediate constituents Unmanly is a complex word.
(2) of a sentence : consisting of a main clause and one or more subordinate clauses
2 : hard to separate, analyze, or solve a complex problem
3 : of, concerned with, being, or containing complex numbers a complex root complex analysis

complex

verb
com·​plex | \ käm-ˈpleks How to pronounce complex (audio) , kəm-ˈpleks, ˈkäm-ˌpleks \
complexed; complexing; complexes

Definition of complex (Entry 3 of 3)

transitive verb

1 : to make complex or into a complex

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Other Words from complex

Adjective

complexly adverb
complexness noun

Verb

complexation \ ˌkäm-​ˌplek-​ˈsā-​shən How to pronounce complexation (audio) , kəm-​ \ noun

Choose the Right Synonym for complex

Adjective

complex, complicated, intricate, involved, knotty mean having confusingly interrelated parts. complex suggests the unavoidable result of a necessary combining and does not imply a fault or failure. a complex recipe complicated applies to what offers great difficulty in understanding, solving, or explaining. complicated legal procedures intricate suggests such interlacing of parts as to make it nearly impossible to follow or grasp them separately. an intricate web of deceit involved implies extreme complication and often disorder. a rambling, involved explanation knotty suggests complication and entanglement that make solution or understanding improbable. knotty ethical questions

The Complex Origins of Complex

The word complex lives up to its name, as it contains multiple parts of speech and senses. It serves as an adjective, a noun, and, less commonly, as a verb. The verb use is the oldest of the three, with an original meaning of “to join or unite.” Complex comes from the Latin complecti, which means “to entwine around, to embrace,” a word that is based in part on plectere (“to braid”). English has a number of other words that can be traced to plectere, including perplex, plexus (“an intricately interwoven combination of elements or parts in a cohering structure”), and amplexus (“the mating embrace of some amphibians, such as frogs and toads”).

Examples of complex in a Sentence

Noun She has a complex about her appearance. a complex of protein molecules Adjective The house's wiring is complex. The situation is more complex than you realize. Verb there's no need to complex what should be a simple process for obtaining a building permit
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Recent Examples on the Web: Noun Britain has in recent years faced a production space crunch, leading to plans for new studio complexes, including one from Comcast/NBCUniversal/Sky, and expansion plans for existing facilities. Georg Szalai, The Hollywood Reporter, "Atlanta's Blackhall Studios to Develop Studio Complex West of London," 19 Feb. 2020 The China Live complex, which includes a $225 tasting menu from the upstairs restaurant Eight Tables, replaced Gold Mountain one year later. Janelle Bitker, SFChronicle.com, "SF’s Chinatown community fears incoming restaurant could bring gentrification," 18 Feb. 2020 Soil is a complex, living, somewhat delicate system. oregonlive, "How to best improve garden soil in preparation for spring planting? Ask an expert," 16 Feb. 2020 The temple complex, which dates to the late 10th and early ninth centuries B.C., was discovered in 2012 at Tel Moza near Jerusalem. Fox News, "Stunning Biblical discovery: Mysterious temple near Jerusalem reveals its secrets," 14 Feb. 2020 Kite Reality, which owns the complex, didn't respond to questions from IndyStar. Kaitlin Lange, Indianapolis Star, "Hamilton Crossing retail center is almost vacant. Carmel wants to help redevelop it.," 13 Feb. 2020 Here are six examples of the complex, underlying elements of vertebrate bones, curated from the National Institute of Health’s online gallery. Popular Science, "These trippy images reveal the colorful inner lives of bones," 4 Feb. 2020 But what Tanowitz and Dinnerstein have created is a complex, exacting performance that preserves a sensation of spontaneity, improvisation, and embrace of error. Erica Getto, The New York Review of Books, "‘A Delightful Flurry of Movement’: Dances to Bach," 1 Feb. 2020 Large banners inside the complex featured the face of Soleimani and other men who were killed alongside him in US drone strikes, ordered by Trump, near the Baghdad airport on Jan. 2. Ben Hubbard, BostonGlobe.com, "Iran’s supreme leader rebukes US in rare Friday sermon," 17 Jan. 2020 Recent Examples on the Web: Adjective Their relationship, at least outwardly, seems as complex as any between coach and player on this team. Zach Osterman, Indianapolis Star, "Like it or not, Devonte Green is the key to IU basketball's 2020 season," 14 Feb. 2020 On the final Sunday in January, Kobe Bryant — a legendary and complex figure within not only basketball and sports but culture writ large — was killed in a helicopter crash on the hills surrounding Calabasas, California. Matt Giles, Longreads, "“The Ugliness of Greatness”: A Kobe Bryant Reading List," 12 Feb. 2020 While these processes can quickly become extremely complex and rigorous, even the most seasoned astrologers still evaluate compatibility based on sun sign. Sophie Saint Thomas, Allure, "Zodiac Love Compatibility: Which Signs to Date — and Which to Avoid," 12 Feb. 2020 In many ways, Sinn Fein are offering relatively simple solutions to pretty complex problems. Nicolae Dumitrache, BostonGlobe.com, "Irish election produces an earthquake as Sinn Fein tops poll," 10 Feb. 2020 The 2014–2016 outbreak in West Africa was the largest and most complex Ebola outbreak since the virus was first discovered. Ginger Christ, cleveland, "Novel coronavirus less deadly than past epidemics, local experts say," 7 Feb. 2020 The history of modern aerospace is littered with ideas such as this, presented as simple solutions to complex problems. Eric Berger, Ars Technica, "Rocket Report: Starlink flies, OneWeb has next mega-constellation launch," 31 Jan. 2020 Scientists in Japan have solved a more complex traveling salesman problem than ever before. Caroline Delbert, Popular Mechanics, "Scientists Solve Most Complex Traveling Salesman Problem Ever," 24 Jan. 2020 He is invariably drawn to figures with complex lives and even multiple identities. Michael Dirda, Washington Post, "We blog, we tweet, we post to Facebook: Let’s instead savor the art of the essay," 19 Dec. 2019

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

Noun

1643, in the meaning defined at sense 1

Adjective

1645, in the meaning defined at sense 1a

Verb

1658, in the meaning defined at sense 1

History and Etymology for complex

Noun

Late Latin complexus totality, from Latin, embrace, from complecti — see complex entry 2

Adjective

Latin complexus, past participle of complecti to embrace, comprise (a multitude of objects), from com- + plectere to braid — more at ply

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Time Traveler for complex

Time Traveler

The first known use of complex was in 1643

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Statistics for complex

Last Updated

23 Feb 2020

Cite this Entry

“Complex.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/complex. Accessed 24 Feb. 2020.

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More Definitions for complex

complex

noun
How to pronounce complex (audio)

English Language Learners Definition of complex

 (Entry 1 of 2)

: a group of buildings, apartments, etc., that are located near each other and used for a particular purpose
: an emotional problem that causes someone to think or worry too much about something
: a group of things that are connected in complicated ways

complex

adjective
How to pronounce complex (audio)

English Language Learners Definition of complex (Entry 2 of 2)

: having parts that connect or go together in complicated ways
: not easy to understand or explain : not simple
grammar : consisting of a main clause and one or more additional clauses

complex

adjective
com·​plex | \ käm-ˈpleks How to pronounce complex (audio) , kəm-ˈpleks, ˈkäm-ˌpleks \

Kids Definition of complex

1 : not easy to understand or explain : not simple complex instructions
2 : having parts that go together in complicated ways a complex invention

complex

adjective
com·​plex | \ käm-ˈpleks How to pronounce complex (audio) , kəm-ˈ How to pronounce complex (audio) , ˈkäm-ˌ \

Medical Definition of complex

 (Entry 1 of 3)

1 : having many varied interrelated parts, patterns, or elements and consequently hard to understand complex behavior a complex personality complex plants and animals
2 : formed by the union of simpler chemical substances complex proteins

complex

noun
com·​plex | \ ˈkäm-ˌpleks How to pronounce complex (audio) \

Medical Definition of complex (Entry 2 of 3)

1 : a group of repressed memories, desires, and ideas that exert a dominant influence on the personality and behavior a guilt complex — see castration complex, electra complex, inferiority complex, oedipus complex, persecution complex, superiority complex
2 : a group of chromosomes arranged or behaving in a particular way — see gene complex
3 : a chemical association of two or more species (as ions or molecules) joined usually by weak electrostatic bonds rather than by covalent bonds
4 : the sum of the factors (as symptoms and lesions) characterizing a disease primary tuberculous complex
com·​plex | \ käm-ˈpleks How to pronounce complex (audio) , kəm-ˈ How to pronounce complex (audio) , ˈkäm-ˌ \

Medical Definition of complex (Entry 3 of 3)

1 : to form into a complex RNA complexed with protein

intransitive verb

: to form a complex hormones which must complex with specific receptors

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