complex

noun
com·​plex | \ˈkäm-ˌpleks \

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, 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, 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, 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

Her company’s Crescent complex—completed in 1986 and containing office, retail and hotel space—transformed an unsightly neighborhood north of downtown Dallas that was formerly occupied by car dealerships. James R. Hagerty, WSJ, "Caroline Hunt, Heiress to Oil Riches, Owned Luxury Hotels and Clung to Frugal Habits," 23 Nov. 2018 That’s too bad, as the series offers a soulful, thoughtful look at the human cost of the military industrial complex, right alongside a twisty conspiracy thriller straight out of the 1970s. Todd Vanderwerff, Vox, "Amazon and Julia Roberts dive into a twisty paranoid thriller.," 20 Nov. 2018 Archaeologists plan to open it, along with a handful of others at the complex, over the next few weeks. Kiona N. Smith, Ars Technica, "Cats, beetles, other mummified animals found—along with a sealed door," 12 Nov. 2018 This cleanser relies on those silver ions, a gentle acid complex, and probiotics to dissolve all of the gunk and grime without disrupting your skin’s delicate oil balance. Megan Mcintyre, Glamour, "This Face Wash Is the Only Thing That Helped My Acne," 29 Aug. 2018 Bay Area drive-ins in the 1970s to 1980s were replaced by condominium complexes, a Kmart and a BART station. Peter Hartlaub, SFChronicle.com, "SF almost had a Sutro Drive-In in 1950, and more local outdoor movie history," 13 July 2018 Applicants may face a wait of up to two years to qualify for housing, but placing their name on the list will ensure they are notified of any openings in one of the town’s four housing complexes, housing authority Director Allen Harrison said. Bill Leukhardt, Courant Community, "Waiting List Open For Southington Housing Authority Apartments," 13 July 2018 Police are investigating an overnight deadly shooting at a northwest Atlanta apartment complex, one of three deadly shootings in the area in a matter of hours. Chelsea Prince, ajc, "Shooting victim’s body found between 2 cars in NW Atlanta," 13 July 2018 When complete, the studio will be Canada’s biggest production complex, overtaking Canadian Motion Picture Park Studios in Burnaby, British Columbia. Erik Heinrich, latimes.com, "Toronto has been a film and TV hub for decades. Now Guillermo del Toro may give the Canadian city an edge," 12 July 2018

Recent Examples on the Web: Adjective

In navigating the complex college admission process, students ought to ask any college that interests them if and how the school factors in race. Charlotte West, Teen Vogue, "What It Means to Check the “Race” Box on College Applications," 25 Sep. 2018 Starting out with something very simple and elementary can warm you up for something more complex and meaningful. Taylor Mead, House Beautiful, "Here’s Your First Look At Cult-Favorite Dishware Designer Rae Dunn’s New Book," 10 Sep. 2018 As a result, her relationship with her kids was very complex and varied from child to child: Prince Charles, 69, Prince of Wales The heir to the throne was born on November 14, 1948. Kayla Keegan, Good Housekeeping, "Inside Queen Elizabeth's Complicated Relationships With Her Children," 18 Aug. 2018 Of course, those antibacterial embalming agents were just one step in what had, by the New Kingdom, become a very complex 70-day process, with the practical work of embalming interwoven with ritual. Kiona N. Smith, Ars Technica, "Ancient Egyptians had been making mummies longer than anyone thought," 16 Aug. 2018 Our Managed Solutions subsidiary, for example, addresses complex workforce organization processes such as mobilization of multi-discipline teams and supply-chain management integration. Ilene Bassler, Houston Chronicle, "Q&A: Strict immigration policies ripple through talent pool," 12 July 2018 Decatur is still waiting on two state-of-the art traffic cabinets, one at each of its two most complex and (for drivers) frustrating intersections, East College Avenue/North McDonough Street and East College/Candler Street. Bill Banks, ajc, "Decatur still waiting on state-of-the art traffic cabinets," 12 July 2018 Answers are never easy, especially with a woman, a performer, as complex and singular as Whitney Houston. Katie Walsh, Detroit Free Press, "Review: Whitney Houston doc is raw and revealing," 5 July 2018 Recovery and analysis of skeletal remains from mass graves is a complex process that requires a high level of expertise, the report said. Bassem Mroue, chicagotribune.com, "Watchdog: Syrian group uncovering Islamic State mass graves needs help," 3 July 2018

Recent Examples on the Web: Verb

Donofrio laments the loss of the Housing Coalition and points to another blow, citing large Johnson County complexes built in the late 1990s with low-income housing tax credits that are now expiring. Lynn Horsley, kansascity, "JoCo agency gave low-income residents a lifeline. Now it's shutting down," 1 July 2018 The housing authority has tried four times to get permission to demolish its Lake Mann Apartments complex off John Young Parkway, also hoping to rebuild that 210-unit community. Kate Santich, OrlandoSentinel.com, "Griffin Park public housing complex could face demolition, relocating 345 residents," 29 June 2018 Petrochemical giant LyondellBasell, for example, is adding to its La Porte complex a $700 million plastics plant expected to produce more than a billion pounds of polyethylene each year. Katherine Blunt, Houston Chronicle, "Houston-area petrochemical producers look overseas to sell plastic," 1 Feb. 2018 The first launch suffered a year’s worth of delays, and the shuttle sat four months on the launch complex 39 as new problems mounted. Joe Pappalardo, Popular Mechanics, "How Astronaut John Young Tamed the Space Shuttle," 8 Jan. 2018 Also, any bid would have to come with the cooperation of the Los Angeles host committee, which recently agreed to complex financial arrangements with the USOC as part of its deal to stage the games. USA TODAY, "USOC CEO to IOC on Russian doping: Time for action is now," 12 Oct. 2017 The storm complex formed under an extremely similar weather pattern to the 2012 derecho. Jason Samenow, Washington Post, "The forgotten derecho of 1954 that slammed Washington," 27 June 2017 Deer and elk have complex digestive systems and have specific dietary needs. Terry Wickstrom, The Denver Post, "Wickstrom: Colorado Parks and Wildlife initiates baiting program to move deer, elk," 31 Jan. 2017 Juan Gavalda, MD, family medicine physician on the medical staff at Methodist Mansfield Medical Center, recommends three things that will help individuals stay energized all day long: ▪ Complex carbs– Angel Biasatti, star-telegram.com, "Staying energized all day long, the healthy way," 20 June 2017

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

30 Nov 2018

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, 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, kəm-ˈ, 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 \

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, kəm-ˈ, 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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