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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QUIZ

THINGAMABOB OR THINGUMMY: CAN YOU DISTINGUISH BETWEEN THE US AND UK TERMS IN THIS QUIZ?

Do you know the difference between everyday US and UK terminology? Test yourself with this quiz on words that differ across the Atlantic.

Question 1 of 7

In the UK, COTTON CANDY is more commonly known as…

candystring

candyfloss

candypuff

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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. 2023

How to use complex in a sentence

The meat is great out of the oven and gets even better if you let it sit in the fridge for several weeks, up to two months — its taste becomes even more complex.
Turn to duck confit for a holiday treat with long-lasting benefits|Mary Beth Albright|November 20, 2020|Washington Post
Just in November, 15 people who have spent time in the media conglomerate’s CBS Broadcast Center complex have tested positive, according to emails sent to employees and reviewed by The Washington Post.
Despite precautions, CBS headquarters reports 15 coronavirus cases amid nationwide surge|Jeremy Barr|November 20, 2020|Washington Post
The game’s story, though, could have revealed more of Hyrule's strange and complex history.
‘Hyrule Warriors: Age of Calamity’: A semi-satisfying new piece of the ‘Zelda’ universe|Harold Goldberg|November 20, 2020|Washington Post
Glenn was a complex man from a complex age, far deeper and more interesting than this book suggests.
Another look at John Glenn through a heroic lens|Francis French|November 20, 2020|Washington Post

“Most of our complex brain functions happen in the prefrontal cortex,” says Reichelt.
Warning! Junk foods can harm a teen’s brain|Sharon Oosthoek|November 19, 2020|Science News For Students
"So it is," said Mrs. Neff, struggling toward him through a sort of panic of complexly moving groups.
What Will People Say?|Rupert Hughes
For a while they had proved fascinating, but a man does not want to have a cartoon, however complexly beautiful, for a wife.
We Can't Have Everything|Rupert Hughes
Staniford complexly raged to see that the anxiety about Hicks had blighted the joy of the day for her.
The Lady of the Aroostook|William Dean Howells
These distinctive stories will be found to be complexly interwoven with all the matters discussed in this address.
The Evolution of the Dragon|G. Elliot Smith
There are indications, however, that the leaves were large and complexly divided.
Ancient Plants|Marie C. Stopes

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

Words related to complex

How to use complex in a sentence

British Dictionary definitions for complex

Derived forms of complex

Word Origin for complex

usage for complex