complex

comparative more complex · comparative nonstandard complexer · superlative most complex · nonstandard superlative complexest

1. Made up of multiple parts; composite; not simple.

   a complex being; a complex idea

   2 more examples

   The human body is a complex system made up of many layers.

   Ideas thus made up of several simple ones put together, I call complex; such as beauty, gratitude, a man, an army, the universe.

   1689 (indicated as 1690), [John Locke], chapter 2, in An Essay Concerning Humane Understanding. […], London: […] Eliz[abeth] Holt, for Thomas Basset, […], →OCLC, book I, page 12

2. Not simple, easy, or straightforward; complicated.

   If, when the actual motions of the heavens are calculated in the best possible way, the process is complex and difficult, and if we are discontented at this, nature, and not the astronomer, must be the object of our displeasure.

   1837, William Whewell, “Inductive Epoch of Hipparchus”, in History of the Inductive Sciences, from the Earliest to the Present Times. […], volume I, London: John W[illiam] Parker, […]; Cambridge, Cambridgeshire: J. and J. J. Deighton, →OCLC, book III (History of Greek Astronomy), section 2 (Estimate of the Value of the Theory of Eccentrics and Epicycles), page 183

   Synonyms: complicated, detailed, difficult, hard, intricate, involved, tough · Antonyms: basic, easy, simple, simplex, straightforward, as a duck takes to water, basic, easy

3. mathematicsHaving the form a + bi, where a and b are real numbers and i is (by definition) the imaginary square root of −1.

   complex number

   1 more example

   function of a complex variable

4. mathematical analysisWhose range is a subset of the complex numbers.

   complex function

5. algebraWhose coefficients are complex numbers; defined over the field of complex numbers.

   complex polynomial

   1 more example

   complex algebraic variety

6. geometryA curve, polygon or other figure that crosses or intersects itself.

plural complexes · nonstandard plural complices

1. A network of interconnected systems.

   military–industrial complex

2. A collection of buildings with a common purpose, such as a university or military base.

   A man at the complex said he had seen the often heavily made-up girls coming and going in luxury vehicles.

   2021 February 6, The Courier-Mail, Brisbane, page 4, column 1

   1 more example

   The south polar region of Promethei Planum developed a Bermuda Triangle reputation. Satellites detected intermittent mass concentrations and magnetic field shifts. In 2148, prospectors working near Deseado Crater discovered an underground complex: a Prothean observation post. The odd phenomena were generated by the operation and discharge of a mass effect core, struggling to function despite fifty millennia of neglect.

   2008, BioWare, Mass Effect (Science Fiction), Redwood City: Electronic Arts, →ISBN, →OCLC, PC, scene: Protheans: Mars Ruins Codex entry

3. An assemblage of related things; a collection.

   This parable of the wedding supper comprehends in it the whole complex of all the blessings and privileges exhibited by the gospel.

   1692–1717, Robert South, Twelve Sermons Preached upon Several Occasions, volume (please specify |volume=I to VI), London

   1. An organized cluster of thunderstorms.
   2. A cluster of wildfires burning in the same vicinity.

      The fire complex began as two separate fires.

      1 more example

      As of early Wednesday, there were at least 25 major wildfires and fire complexes, the term given to multiple fires in a single geographic area, burning in California, Christine McMorrow, a Cal Fire information officer, said.

      2020 September 16, “Millions of acres burn in California as weather improves in Northwest.”, in The New York Times, retrieved 16 Sep 2020

   3. biologyA group of closely related species, often distinguished only with difficulty by traditional morphological methods.

      Since then, a good deal of research has documented and concluded that the nominal species A. fraterculus actually comprises an unresolved complex of cryptic species.

      2015 November 26, Mosè Manni et al., “Relevant genetic differentiation among Brazilian populations of Anastrepha fraterculus (Diptera, Tephritidae)”, in ZooKeys, volume 540, →DOI

      Synonyms: species complex, species group, species aggregate

4. human sciencesA group of emotionally charged ideas or mental factors, unconsciously associated by the individual with a particular subject, arising from repressed instincts, fears, or desires and often resulting in mental abnormality.

   Jim has a real complex about working for a woman boss.

   Synonyms: constellation

   1. human sciencesA fixed mental tendency or obsession.

      Synonyms: constellation

5. chemistryA structure consisting of a central atom or molecule weakly connected to surrounding atoms or molecules, as for example coordination compounds in inorganic chemistry and protein complexes in biochemistry.

   1 more example

   Oxygen levels on Earth skyrocketed 2.4 billion years ago, when cyanobacteria evolved photosynthesis:[…]. The evolutionary precursor of photosynthesis is still under debate, and a new study sheds light. The critical component of the photosynthetic system is the “water-oxidizing complex”, made up of manganese atoms and a calcium atom.

   2013 September-October, Katie L. Burke, “In the News”, in American Scientist

6. mathematicsA complex number.

   The interesting aspect here is that U₃ is irreducible, even though all irreps over the complexes are one-dimensional because ℤ₄ is abelian.

   1996, Barry Simon, Representations of Finite and Compact Groups, page 50

7. human sciencesA multimorphemic word, one with several parts, one with affixes.

present singular third person complexes · participle present complexing · participle past complexed · past complexed

1. intransitivechemistryTo form a complex with another substance.
2. transitiveTo complicate.