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

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 At this apartment complex in Vilnius, Lithuania, Heima Architects put the theory to test. Liz Stinson, Curbed, "These tiny apartments show how to live cozy in 270 square feet," 26 July 2018 The apartment manager was placed on administrative leave after the July 6 incident at the River Crossing at Keystone apartment complex. Vic Ryckaert, Indianapolis Star, "IMPD investigating officer involved in alleged profiling incident at swimming pool," 13 July 2018 He was arrested Wednesday evening at the apartment complex where Meroney was found dead with a gunshot shot wound. Fernando Ramirez, Houston Chronicle, "Suspect in Austin shooting spree had ties to Texas politics," 13 July 2018 Orange County deputies on Friday arrested a suspect in the shooting that injured a man at an apartment complex popular with UCF students. Michael Williams, OrlandoSentinel.com, "Deputies arrest suspect in shooting at UCF-area apartment," 13 July 2018 Firefighters responded to reports of the explosion about 2:20 p.m. at a two-story garden-style apartment complex on Bacon Street near Cape May Avenue, according to fire officials. Alex Riggins, sandiegouniontribune.com, "Reported explosion at Ocean Beach apartment results in small fire, sends 1 to hospital with burns," 11 July 2018 Vince Lewis, a Phoenix police spokesman, said officers found two replica guns at the scene of the shooting at an apartment complex near Seventh Street and Greenway Parkway. Kimberly Rapanut, azcentral, "Man shot by Phoenix police officer was holding replica handgun," 10 July 2018

Recent Examples on the Web: Adjective

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 The faceted metal frames come in an endless multitude of shapes, from modernist cubes and spheres to more complex house-like silhouettes with an almost Victorian feel. Michele Petry, House Beautiful, "Until It’s Gardening Weather Again, I’ll Be Staring at These Tabletop Terrariums," 21 Feb. 2019 Cantwell said, adding that the record-setting Carlton complex in 2014 left an impression. Evan Bush, The Seattle Times, "Here’s what the massive public-lands bill means for conservation, climate change in Washington state," 12 Feb. 2019 That, coupled with the small size and faintness of Ultima Thule, creates an even more complex trial for the scientists and engineers to overcome. Loren Grush, The Verge, "On New Year’s Day, a spacecraft will zoom by the most distant object humanity has ever visited," 27 Dec. 2018 Chats about art and sports quickly expanded to include more complex topics. Sara Benincasa, Glamour, "I Had an Affair With a Married Man—and We Never Even Kissed," 18 Oct. 2018 Rawlings said Sunday that the 30-year-old officer , Amber Guyger, drove to her apartment complex Thursday night after her shift. Fox News, "The Latest: Grand jury to hear case against Dallas cop," 10 Sep. 2018 Instead, an international team of scientists found that the genetic diversity of the region is more complex than initially suspected, with Hòabìnhian, East Asian, Southeast Asian and Vietnamese populations all contributing to the mix. Meilan Solly, Smithsonian, "Ancient DNA Offers Insight on Origins of Southeast Asia’s Present-Day Population," 11 July 2018 In recent years, the fight against malaria in Central America has grown more complex. Emily Baumgaertner, New York Times, "In a Rare Success, Paraguay Conquers Malaria," 6 July 2018

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

23 Mar 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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