from The American Heritage® Dictionary of the English Language, 5th Edition.

  • adjective Consisting of interconnected or interwoven parts; composite.
  • adjective Composed of two or more units.
  • adjective Difficult to understand for being intricate or involved; complicated.
  • adjective Consisting of at least one bound form. Used of a word.
  • adjective Consisting of an independent clause and at least one other independent or dependent clause. Used of a sentence.
  • noun A whole composed of interconnected or interwoven parts.
  • noun A building or group of buildings used for a single purpose.
  • noun In psychology, a group of related, often repressed ideas and impulses that compel characteristic or habitual patterns of thought, feelings, and behavior. No longer in scientific use.
  • noun An exaggerated or obsessive concern or fear.
  • noun Medicine The combination of factors, symptoms, or signs of a disease or disorder that forms a syndrome.

from The Century Dictionary.

  • noun Anything consisting in or formed by the union of interconnected parts; especially, an assemblage of particulars related as parts of a system.
  • noun In geometry, a continuous, triply infinite system of infinite straight lines; the whole of any kind of forms in space fulfilling one condition: thus, all the lines that cut a given curve in space constitute a complex.
  • To combine intricately; involve; mix up.
  • Composed of interconnected parts; formed by a combination of simple things or elements; including two or more connected particulars; composite; not simple: as, a complex being; complex ideas; a complex term.
  • Involved; intricate; complicated; perplexing.
  • In the theory of numbers, any expression in the form ai + bj +, etc., where a, b, etc., are integers, and i, j, etc., are peculiar units.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective Composed of two or more parts; composite; not simple.
  • adjective Involving many parts; complicated; intricate.
  • adjective See Fraction.
  • adjective (Math.) in the theory of numbers, an expression of the form a + b√-1, when a and b are ordinary integers.
  • noun Assemblage of related things; collection; complication.
  • noun (Geom.) all the possible straight lines in space being considered, the entire system of lines which satisfy a single relation constitute a complex. The lines which satisfy two relations constitute a congruency of lines; as, the entire system of lines, each one of which meets two given surfaces, is a congruency.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • adjective Made up of multiple parts; intricate or detailed.
  • adjective Not simple or straightforward.
  • adjective mathematics Of a number, of the form a + bi, where a and b are real numbers and i is the square root of −1.
  • adjective geometry A curve, polygon or other figure that crosses or intersects itself.
  • noun A problem.
  • noun A collection of buildings with a common purpose, such as a university or military base.
  • noun A psychologically based dislike or fear of a particular thing.
  • noun A thunderstorm that forms when two storm fronts collide.
  • noun chemistry A structure consisting of a central atom or molecule weakly connected to surrounding atoms or molecules.
  • verb chemistry, intransitive To form a complex with another substance

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a conceptual whole made up of complicated and related parts
  • noun a compound described in terms of the central atom to which other atoms are bound or coordinated
  • noun a whole structure (as a building) made up of interconnected or related structures
  • adjective complicated in structure; consisting of interconnected parts
  • noun (psychoanalysis) a combination of emotions and impulses that have been rejected from awareness but still influence a person's behavior


from The American Heritage® Dictionary of the English Language, 4th Edition

[Latin complexus, past participle of complectī, to entwine; see complect.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From French complexe, from Latin complexus, past participle of complectī ("to entwine, encircle, compass, infold"), from com- ("together") and plectere ("to weave, braid"). See complect.


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  • Then is Perception, in the prefent way of confidering it, faid to be fimple, when the Objeft of it is fimple, and then complex when the Objeft of it is complex* And fince the intire and ade - quate Objeft of Thought (as will hereafter ap - pear) is cpmprifed within the compafs of Ideas and of their Relations, we may more explicitly fay that then is Perception fimple when it is tlie Contemplation of Ideas only, and then complex when with the Ideas it takes in alfo the Confideration of their Relations and effen - tial Habitudes.

    An Essay Towards the Theory of the Ideal Or Intelligible World. Design'd for ... 1704

  • 78 Day 4 The variable z so defined has now a real and an imaginary part that can be individually addressed using, respectively, the syntax: __real__ z and __imag__ z Similarly, the next declaration produces a complex variable of 32-bit integer type: __complex__ int x;

    Recently Uploaded Slideshows 2009

  • I shuddered a little on encountering the phrase "complex polyvocal, transhistorical schematic."

    Keeper of the Affirming Flame Brad Leithauser 2011

  • The term complex is used by doctors to describe a person who is between being fully alert and unconscious.

    WebMD Health 2009

  • The term complex is used by doctors to describe a person who is between being fully alert and unconscious.

    WebMD Health 2009

  • The term complex is used by doctors to describe a person who is between being fully alert and unconscious.

    WebMD Health 2009

  • The commission will also work out a strategy to tackle what it calls the "complex phenomenon" of illegal music downloading.

    EU Lays Out New Plans on Piracy, Music Rights Frances Robinson 2011

  • Developed by Heydey Partnership, the complex is aiming to prove that modern sustainably built homes can be affordable as well.

    Adrianne Jeffries | Inhabitat 2009

  • But believe me when I say this complex is there, an ugly little current pushing female characters toward one pole or the other.

    Virgins and whores at SF Novelists 2009

  • Their incoming top officer, General Jim Amos, recently told an audience the Corps has long been adept at quickly solving what he called complex and nasty security problems.

    Marines Need To Regain 'Maritime Soul,' Gates Says 2010

  • Alongside this novelty factor, her path to fame was smoothed by what people on the subcontinent call the “gora complex”, a term that describes preferential treatment given to white people. (Gora means “white person” in Urdu.)

    How western travel influencers got tangled up in Pakistan's politics Samira Shackle 2021


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  • complex number (n): (mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1. The term "a" is the real part and the term "bi" is the imaginary part.

    May 13, 2008

  • The verbal use appears to be beakerspeak.

    December 18, 2015