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
2 : chelate

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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

Despite what Apple might be able to offer in terms of either privacy or exclusive content, though, the company can't avoid the problem that's beginning to loom over the tech-entertainment complex. Eric Limer, Popular Mechanics, "How Many Subscriptions Can You Handle?," 25 Mar. 2019 Metals prices were mixed on Thursday, with the precious complex broadly boosted by the U.S. Federal Reserve’s decision not to raise interest rates further this year. Christopher Alessi, WSJ, "Gold Gets a Boost From Fed’s Dovish Stance," 21 Mar. 2019 The sprawling re-vamp of MTA's rail yards boasts two apartment complexes complete with private entrances and keyless entry for its wealthy owners. House Beautiful, "Everything You Need to Know About Hudson Yards, New York's $25 Billion Neighborhood," 19 Mar. 2019 The president has 58 million Twitter followers and a vast conservative media-industrial complex that will happily amplify his comments. Sean Illing, Vox, "How the media should respond to Trump’s lies: State of the Union edition," 5 Feb. 2019 First stop: Topkapı Palace, a.k.a. the Seraglio, a 15th-century Ottoman palace and municipal complex that served as the heart of the empire for 380 years. Ashlea Halpern, Condé Nast Traveler, "Three Days In Istanbul," 28 Dec. 2018 But those looking for something a little more complex should look out for the Switch’s first mainline Pokémon adventure, which promises to be a more traditional role-playing game. Andrew Webster, The Verge, "The 40 games we can’t wait to play in 2019," 26 Dec. 2018 Photo: Hans Pennink/Associated Press In the letter, the chief judge said filling judgeships would help reduce the number of criminal cases involving people detained at the jail complex on Rikers Island, an effort Mr. de Blasio has supported. Corinne Ramey, WSJ, "Court Officials Blast Mayor de Blasio for Delays on Judges," 2 Jan. 2019 The shooting took place Wednesday night as a unit of nine officers served a search warrant at an apartment complex about 20 miles south of the nation's capital. Stephen Sorace, Fox News, "Two Maryland officers injured in shooting had served warrant to wrong apartment, police say," 21 Sep. 2018

Recent Examples on the Web: Adjective

Artificial intelligence has mastered some of the world’s most complex games, beating top players at chess, Go and even StarCraft II, a real-time strategy computer game. Asa Fitch, WSJ, "Why the Card Game Hanabi Is the Next Big Hurdle for Artificial Intelligence," 29 Mar. 2019 This is because getting pregnant requires a specific and complex chain of events to happen successfully. Kasandra Brabaw, SELF, "Can You Get Pregnant From Precum?," 7 Mar. 2019 The Nomination Process This part is the most complex. Katherine J. Igoe, Marie Claire, "How Do the Oscars Work? Here's Your Step-by-Step Primer," 24 Feb. 2019 This juicy, light-hearted yet subtly complex red is super food friendly and works really well with turkey and cranberries. Laura Giannatempo, Condé Nast Traveler, "The Best Wine to Pair With Turkey, According to Wine Experts," 15 Nov. 2018 The Xbox One console can already stream your games to Windows 10 PCs over your local network, but that’s a totally different and far less complex technology than xCloud. Brad Chacos, PCWorld, "Microsoft's Project xCloud service will stream Xbox games to PCs, tablets, and phones," 8 Oct. 2018 And too often, help for the poor comes in ways that are cruel, inefficient, paternalistic or complex. The Economist, "Capitalism needs a welfare state to survive," 12 July 2018 In short, defensive structure, set pieces and vigor are probably easier to implement in a few short weeks of national team training time than complex attacking patterns or individual game-breaking skill and flair. Brian Straus, SI.com, "The Factors and Figures Behind Europe's World Cup Dominance Trend," 8 July 2018 The wine then ages in-bottle for at least 18 months (for franciacorta's riserva style that can be up to 60 months) to develop a deeper, more complex flavor profile. Lauren Hubbard, Town & Country, "Prosecco Isn't the Champagne of Italy, Franciacorta Is," 15 Mar. 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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Statistics for complex

Last Updated

6 Apr 2019

Look-up Popularity

Time Traveler for complex

The first known use of complex was in 1643

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More Definitions for complex

complex

noun

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

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

complex

transitive verb
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
2 : chelate

intransitive verb

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

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Comments on complex

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