complex

[ adjective, verb kuhm-pleks, kom-pleks; noun kom-pleks ]

/ adjective, verb kəmˈplɛks, ˈkɒm plɛks; noun ˈkɒm plɛks /

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See synonyms for: complex / complexes on Thesaurus.com

adjective

composed of many interconnected parts; compound; composite: a complex highway system.

characterized by a very complicated or involved arrangement of parts, units, etc.: complex machinery.

so complicated or intricate as to be hard to understand or deal with: a complex problem.

Grammar.

(of a word) consisting of two parts, at least one of which is a bound form, as childish, which consists of the word child and the bound form -ish.
complex sentence.

Mathematics. pertaining to or using complex numbers: complex methods; complex vector space.

noun

an intricate or complicated association or assemblage of related things, parts, units, etc.: the entire complex of our educational system; an apartment complex.

Psychology. a system of interrelated, emotion-charged ideas, feelings, memories, and impulses that is usually repressed and that gives rise to abnormal or pathological behavior.

a fixed idea; an obsessive notion.

Mathematics.

an arbitrary set of elements of a group.
a collection of simplexes having specified properties.

Also called coordination compound. Chemistry. a compound in which independently existing molecules or ions of a nonmetal (complexing agent ) form coordinate bonds with a metal atom or ion.Compare ligand (def. 2).

Biochemistry. an entity composed of molecules in which the constituents maintain much of their chemical identity: receptor-hormone complex, enzyme-substrate complex.

verb (used with object)

Chemistry. to form a complex with.

verb (used without object)

Chemistry. to form a complex.

OTHER WORDS FOR complex

3 knotty, tangled, labyrinthine.

6 network, web, tangle, labyrinth.

See synonyms for complex on Thesaurus.com

OPPOSITES FOR complex

2, 3 simple.

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Origin of complex

First recorded in 1645–55; 1905–10 for def. 7; adjective from Latin complexus, past participle of complectī, complectere “to embrace, encompass, include,” equivalent to complect- (see complect) + -tus past participle suffix; noun from Late Latin complexus “totality, complex” (Latin: “inclusion, grasping, embrace”), equivalent to complect(ere) + -tus suffix of verb action; reanalysis of the Latin verb as “to intertwine (completely)” influenced sense of the adjective

OTHER WORDS FROM complex

com·plex·ly, adverbcom·plex·ness, nouno·ver·com·plex, adjectivequa·si-com·plex, adjective

qua·si-com·plex·ly, adverbsu·per·com·plex, adjectiveun·com·plex, adjectiveun·com·plex·ly, adverbun·com·plex·ness, noun

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use complex in a sentence

The largely self-contained world of the apartment complex feeds into a school district in Elmhurst, a more affluent city just south of Bensenville.
Inside the Lives of Immigrant Teens Working Dangerous Night Shifts in Suburban Factories|by Melissa Sanchez|November 19, 2020|ProPublica
They’re simple pieces of engineering that solve sometimes complex problems affecting human eyes, allowing wearers to take in the beauty of the natural world.
The best ways to stop a mask from fogging up your glasses, ranked|Sandra Gutierrez G.|November 18, 2020|Popular-Science
The future will include algorithms that teach computers how to better understand more complex data.
Explainer: What is an algorithm?|Melissa L. Weber|November 12, 2020|Science News For Students
One of the challenges of science is understanding complex relationships among large numbers of uncontrolled variables.
Are We Wired to Be Outside? - Issue 92: Frontiers|Grigori Guitchounts|November 11, 2020|Nautilus

Bond issuance, for instance, is both complex and slow enough that it doesn’t make sense below a certain amount.
The era of Central Bank Coins is upon us. Here’s why.|dzanemorris|November 11, 2020|Fortune
A simple proposition consisting of three words, and a complexed one, not ordinarily short of five.
The Works of Sir Thomas Browne|Thomas Browne
For a long moment he considered, for no words seemed effectual to deliver his complexed mind.
The Unknown Sea|Clemence Housman

British Dictionary definitions for complex

complex

/ (ˈkɒmplɛks) /

adjective

made up of various interconnected parts; composite

(of thoughts, writing, etc) intricate or involved

grammar

(of a word) containing at least one bound form
(of a noun phrase) containing both a lexical noun and an embedded clause, as for example the italicized parts of the following sentence: I didn't know the man who served me
(of a sentence) formed by subordination of one clause to another

maths of or involving one or more complex numbers

noun

a whole made up of interconnected or related partsa building complex

psychoanal a group of emotional ideas or impulses that have been banished from the conscious mind but that continue to influence a person's behaviour

informal an obsession or excessive fearhe's got a complex about cats

Also called: coordination compound a chemical compound in which molecules, groups, or ions are attached to a central metal atom, esp a transition metal atom, by coordinate bonds

any chemical compound in which one molecule is linked to another by a coordinate bond

Derived forms of complex

complexly, adverbcomplexness, noun

Word Origin for complex

C17: from Latin complexus, from complectī to entwine, from com- together + plectere to braid

usage for complex

Complex is sometimes wrongly used where complicated is meant. Complex is properly used to say only that something consists of several parts. It should not be used to say that, because something consists of many parts, it is difficult to understand or analyse

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

complex

OTHER WORDS FOR complex

OPPOSITES FOR complex

Origin of complex

OTHER WORDS FROM complex

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How to use complex in a sentence

British Dictionary definitions for complex

Derived forms of complex

Word Origin for complex

usage for complex