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 But a report published in January by the National Audit Office (NAO), Parliament’s spending watchdog, suggests that Britain’s nuclear complex is in the throes of crisis. The Economist, "Defence Botched nuclear projects put the future of Britain’s defences at risk," 8 Feb. 2020 The newsroom and reporters from its parent company, Advance Local, also tested public housing complexes for radon in six cities. oregonlive, "HUD pledges to seek ‘record’ amount of money for hazards such as radon; keeps senators at bay," 5 Feb. 2020 McDaniel, who also built the Steel House Lofts complex at 1401 S. Flores St., didn’t respond to inquiries. Madison Iszler, ExpressNews.com, "Commissioners OK designs for eight-story project near La Villita," 5 Feb. 2020 Trump’s name has also been removed from other residential complexes around the country. Caitlin Yilek, Washington Examiner, "West Palm Beach condo residents vote against restoring Trump name atop buildings," 5 Feb. 2020 Left behind aboard the lab complex will be Expedition 62 commander Oleg Skripochka and Koch's spacewalking partners, astronauts Jessica Meir and Drew Morgan. William Harwood, CBS News, "Christina Koch heads home, setting new record for female astronauts," 5 Feb. 2020 The Maisy Battery is now open to the public, although, as Gates found, the complex is still revealing its secrets. Fox News, "Secret Nazi World War II bunkers discovered near D-Day beaches," 5 Feb. 2020 Springfield-area legislators have pressed the state for years to renovate or replace the court complex. Brian Macquarrie, BostonGlobe.com, "Illnesses spark concerns about workplace hazards at Springfield courthouse," 4 Feb. 2020 Spooned out of a black Staub cocotte, the meatballs are a bit sweet, a bit salty, the sauce complex. TheWeek, "Traveling across Belgium to build a better meatball," 2 Feb. 2020 Recent Examples on the Web: Adjective To make sure their systems comply, companies rely on human experts to interpret the laws – a complex and time-consuming task for organizations that constantly launch and update services. Karuna Pande Joshi, The Conversation, "AI could constantly scan the internet for data privacy violations, a quicker, easier way to enforce compliance," 7 Feb. 2020 An untitled work from 1958 looks like a rendering of a complex system floating in oceanic turquoise space. Jillian Steinhauer, New York Times, "Zilia Sánchez’s Island of Erotic Forms," 6 Feb. 2020 The complex system tracks each interaction a person has with Oregon’s child welfare system, from calls to the state child abuse hotline to checks to make sure foster homes are safe for children. oregonlive, "Oregon’s hard-to-use database on child abuse reports puts children at risk, audit finds," 5 Feb. 2020 The breakdown pointed to the complex system Iowa Democrats use and the difficulties that go with it. Dan Balz, BostonGlobe.com, "Uncertainty plagues first voting of 2020," 4 Feb. 2020 The planet’s global carbon cycle is a complex system in which carbon is naturally stored and exchanged among the atmosphere, land, ocean, rocks and living organisms. NBC News, "Australia wildfires unleash millions of tons of carbon dioxide," 22 Jan. 2020 Officials have said changes have been made to help simplify the complex system and to give more teachers the chance to earn higher salaries. Dallas News, "Teachers turn to Texas Supreme Court in latest attempt to battle Dallas’ merit-based pay system," 17 Jan. 2020 Rather, a complex systems approach that accounts for nonlinearities and networks of interactions is what is needed. Jennifer Ouellette, Ars Technica, "Clustering pattern of Azteca ant colonies may be due to a Turing mechanism," 2 Jan. 2020 Whether it’s city planners, the foundation staffs, bankers or neighborhood activists, more and more of these players have learned to reduce the barriers and make a complex system of investment work. John Gallagher, Freep.com, "Departing Free Press columnist John Gallagher pens open letter to Detroiters," 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

9 Feb 2020

Cite this Entry

“Complex.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/complex?pronunciation&lang=en_us&dir=c&file=comple15. Accessed 20 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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Comments on complex

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