complex

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

adjective

1. composed of many interconnected parts; compound; composite:

   a complex highway system.

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

   complex machinery.

   Antonyms: simple

3. so complicated or intricate as to be hard to understand or deal with:

   a complex problem.

   Synonyms: labyrinthine, tangled, knotty

   Antonyms: simple

4. Grammar.
   1. (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.
   2. complex sentence.
5. Mathematics. pertaining to or using complex numbers:

   complex methods; complex vector space.

noun

1. an intricate or complicated association or assemblage of related things, parts, units, etc.:

   the entire complex of our educational system; an apartment complex.

   Synonyms: labyrinth, tangle, web, network

2. 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.
3. a fixed idea; an obsessive notion.
4. Mathematics.
   1. an arbitrary set of elements of a group.
   2. a collection of simplexes having specified properties.
5. 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 ).
6. 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)

1. Chemistry. to form a complex with.

verb (used without object)

1. Chemistry. to form a complex.

complex

/ ˈkɒmplɛks /

adjective

1. made up of various interconnected parts; composite
2. (of thoughts, writing, etc) intricate or involved
3. grammar
   1. (of a word) containing at least one bound form
   2. (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
   3. (of a sentence) formed by subordination of one clause to another
4. maths of or involving one or more complex numbers

noun

1. a whole made up of interconnected or related parts

   a building complex

2. 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
3. informal.
   an obsession or excessive fear

   he's got a complex about cats

4. Also calledcoordination 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
5. any chemical compound in which one molecule is linked to another by a coordinate bond

Usage

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

Derived Forms

• ˈcomplexly, adverb
• ˈcomplexness, noun

Other Words From

• com·plexly adverb
• com·plexness noun
• over·com·plex adjective
• quasi-com·plex adjective
• quasi-com·plexly adverb
• super·com·plex adjective
• uncom·plex adjective
• uncom·plexly adverb
• uncom·plexness noun

Word History and Origins

Origin of complex¹

First recorded in 1645–55; 1905–10 complex fordef 7; adjective from Latin complexus, past participle of complectī, complectere “to embrace, encompass, include,” equivalent to complect- ( 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

Word History and Origins

Origin of complex¹

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

Example Sentences

The researchers assumed the brain's frontal cortex, which orchestrates complex thoughts and behaviors, was somehow communicating to a brainstem region called the medulla, which controls automatic breathing.

From Science Daily

In both computational models and laboratory experiments, the team of scientists used cell density as an effective tool for controlling how mouse cells pattern themselves into complex structures.

From Science Daily

The Yakimovich group "Machine Learning for Infection and Disease" aims to understand the complex network of molecular interactions that is active after the body has been infected with a pathogen.

From Science Daily

But Rob Jones, director of operations at the NCA, says cracking down on the trade is complex - and even more difficult than policing the movement of illegal drugs.

From BBC

“I felt his music was complex, beautiful, harmonically and textually varied,” says Coppola, “and interesting.”

From Los Angeles Times

Related Words

• complicated
• convoluted
• disturbing
• intricate
• obscure
• perplexing
• sophisticated