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 Five men were shot Wednesday night in San Jose when an unknown man walked up to the group of people standing on the driveway of an apartment complex and opened fire, police said. Alejandro Serrano, SFChronicle.com, "Lone gunman injures 5 men in San Jose shooting, all victims expected to survive," 28 May 2020 Two men were killed in separate shootings at apartment complexes on the northwest side and in Lawrence early Thursday, police said. Vic Ryckaert, Indianapolis Star, "2 men killed in separate shootings at Indy-area apartment complexes," 28 May 2020 Sanders, a 52-year-old black male, died May 21 at UAB Hospital after being found unresponsive outside an apartment complex in the 1700 block of 32nd Place North. Carol Robinson | Crobinson@al.com, al, "Family sought for 3 Birmingham residents who died this month," 28 May 2020 As the standoff played out in the parking lot of the apartment complex, residents, at Mills urging, called the police. Konstantin Toropin, CNN, "An Arizona man was arrested after pointing a gun at a DoorDash delivery man," 27 May 2020 Baimbridge added that four months ago, the same man led Texas Department of Public Safety troopers on a chase through the same apartment complex. Julian Gill, Houston Chronicle, "HPD: Man arrested in second standoff with police in four months," 25 May 2020 One man died and another was injured in a shooting at an east-side apartment complex Sunday. Vic Ryckaert, The Indianapolis Star, "1 killed, 1 hurt in shooting at east-side apartment complex," 24 May 2020 When two women from an apartment complex heard the commotion and came outside, Jones was able to run through a shallow creek and call the police, Middlebrooks said. NBC News, "Brutal beating in Iowa should be investigated as hate crime, NAACP says," 21 May 2020 According to reports, police arrested Donjuan after video surveillance cameras showed him enter the woman’s gated apartment complex by following another car inside the gate, and leave moments after the shooting. Elizabeth Zavala, ExpressNews.com, "San Antonio teen accused of stabbing mom, sister indicted on capital murder charges," 18 May 2020 Recent Examples on the Web: Adjective Kletter’s writing is gorgeous and poignant, and her characters are incredibly complex. Seija Rankin, EW.com, "What's in a Page: Emily Henry's Beach Read was built on yogurt and good lighting," 26 May 2020 The notion of patriotism is particularly complex here. Suzanne Sataline, The Atlantic, "The Challenge to China From Hong Kong's 'Sense of Country'," 21 May 2020 Although the majority of emerging zoonotic diseases have originated in wildlife, not livestock or pets, Barton Behravesh notes that interactions between humans and other species are incredibly complex. Stacey Mckenna, Scientific American, "Human Viruses Can Jump into Animals, Too—Sowing the Seeds of Future Epidemics," 20 May 2020 Negotiations with entertainment unions about restarting are complicated, and HBO, with shows that often feature large casts in multiple cities or countries, is especially complex. Gerry Smith, Bloomberg.com, "HBO Max Viewers May Soon Be Able to Skip Opening Credits in Break From Tradition," 20 May 2020 Ascent Aviation spokeswoman Annette Feasel said the process of storing an aircraft is complex. John D'anna, azcentral, "Grounded in Arizona: Ghost flights arrive but don't leave as ailing airlines park fleets," 17 May 2020 The details of the deal, worth $261 million in 1989, are complex. At A Great Price, ProPublica, "Sears’ Headquarters Was Supposed to Turn a Sleepy Suburb Into a Boomtown. It Never Happened.," 15 May 2020 This example is complex, showing baking spice, citrus peel, dried fig, and wood notes, plus a rich mouth-feel. Dallas News, "Throw a wine and jamon pairing at home with takeout from Enrique Tomas and some stunning wines," 15 May 2020 The kind of code that allows for multiple drones to fly alongside another aircraft and operate with some degree of autonomy would need to be highly complex. Rob Verger, Popular Science, "Boeing’s new autonomous fighter jet has a pop-off, swappable nose," 15 May 2020

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

31 May 2020

Cite this Entry

“Complex.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/complex. Accessed 3 Jun. 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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Comments on complex

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