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

The housing complex surrounding the pond, the Grand Isles, was under construction when Moldt disappeared, according to the Charley Project and local news reports. The Washington Post, oregonlive, "For 22 years, his disappearance was a mystery; then, someone spotted something odd in a Google Earth photo," 14 Sep. 2019 Suspicious, Old Detroit Road On Sept. 1 officer responded to an apartment complex after a resident discovered graffiti and a bag smoking in the building. cleveland.com, "Report of woman doing gymnastics in a grocery store: Rocky River Police Blotter," 12 Sep. 2019 The 150-square-mile complex, which includes the famous Angkor Wat Temple, is Siem Reap’s biggest tourist draw. Kareena Gianani, National Geographic, "Explore Cambodia’s ancient stone city," 10 Sep. 2019 As recently as January of last year, a temporary 31-year-old worker jumped to death from an apartment complex at the Zhengzhou factory. Echo Huang, Quartz at Work, "In China’s “iPhone City,” overtime is used for both punishment and reward," 9 Sep. 2019 Two cats died in a fire at an apartment complex in Maryland, officials said. Washington Post, "Two cats dead, no humans hurt in apartment complex fire in Maryland," 22 Aug. 2019 Carla Yanni can’t decide if the most over-the-top student housing amenity she’s seen is the pet-washing station at a LaSalle University dorm or the lazy river winding through an apartment complex near Arizona State. Patrick Sisson, Curbed, "Back on campus, students confront a challenging housing market," 20 Aug. 2019 Joseph Thorpe was taken into custody at an apartment complex in Manchester on Wednesday and was charged with murder and criminal possession of a firearm. Kathleen Mcwilliams, courant.com, "Hartford police make arrest in Aug. 3 homicide," 15 Aug. 2019 The child wasn't breathing around 8:30 p.m. when officers arrived at an apartment complex in the 100 block of East Plaza Boulevard, police said. Loyd Brumfield, Dallas News, "Hurst police investigate death of 4-month-old child found not breathing," 15 Aug. 2019

Recent Examples on the Web: Adjective

And if the clearest philosophical gulf separated Mr. Biden from the prominent populists who flanked him — Mr. Sanders and Ms. Warren — the debate made plain that the party was in the midst of a far more complex process of defining its identity. Jonathan Martin, New York Times, "Attacks on Biden in Debate Highlight Divide Over the Obama Legacy," 13 Sep. 2019 But the reality is more complex and, in some ways, more ennobling. Timothy Sandefur, National Review, "The Anti-Slavery Constitution," 12 Sep. 2019 The dials of these niche watches are made out of the MiG’s aluminium skin, modified through a complex process. Manavi Kapur, Quartz India, "Abhinandan Indians! Your watch could now carry a piece of IAF history," 11 Sep. 2019 Through Lydia’s narration, Atwood allows us access to a mind far more complex, with many more shades of grey, than her original novel let on. Lucy Feldman, Time, "Let's Break Down the Most Mysterious Parts of The Testaments, With a Little Help From Margaret Atwood," 10 Sep. 2019 The Debt That Lies Ahead Despite the complex process, California is generous compared with most states. Jenny Gold, The Mercury News, "A young woman, a wheelchair and the fight to take her place at Stanford," 8 Sep. 2019 The point here is that tapping into retirement accounts can be complex, with numerous tax wrinkles. Russ Wiles, azcentral, "How to make your retirement earnings recession-proof," 8 Sep. 2019 Among them: its deft sound design and cinematography; its rending performances; its complex — or not, since the debating has already begun — grasp of race. Lisa Kennedy, The Know, "From “The Two Popes” to a Judy Garland biopic, the best films from the 2019 Telluride Film Festival," 5 Sep. 2019 Winners will be revealed at an awards reception Nov. 13 at Cleveland’s largest fine arts complex, smARTspace. Kristen Davis, cleveland.com, "Final week to nominate people who have made substantial contributions to Cleveland’s economic development: Homegrown Heroes," 26 Aug. 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

5 Oct 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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